Java/C++/C#: Revert the join order fix from #2872

This revert brings back the performance problems in
`DataFlowImplLocal.qll` so they can be fixed in a different way. The fix
in #2872 was asymptotically good but had undesired overhead because it
introduced another predicate in the SCC that existed purely for join
ordering.

I did the revert by inlining the helper predicate, eliminating the
`enclosing` variable, and re-ordering the resulting lines to what they
were before #2872.

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl.qll

@@ -2293,12 +2293,13 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
  * a callable is recorded by `cc`.
  */
 private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCtx sc, AccessPath ap) {
-  exists(
-    AccessPath ap0, Node midnode, Configuration conf, DataFlowCallable enclosing,
-    LocalCallContext localCC
-  |
-    pathIntoLocalStep(mid, midnode, cc, enclosing, sc, ap0, conf) and
-    localCC = getLocalCallContext(cc, enclosing)
+  exists(AccessPath ap0, Node midnode, Configuration conf, LocalCallContext localCC |
+    midnode = mid.getNode() and
+    conf = mid.getConfiguration() and
+    cc = mid.getCallContext() and
+    sc = mid.getSummaryCtx() and
+    localCC = getLocalCallContext(cc, midnode.getEnclosingCallable()) and
+    ap0 = mid.getAp()
   |
     localFlowBigStep(midnode, node, true, _, conf, localCC) and
     ap = ap0
@@ -2331,20 +2332,6 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   pathThroughCallable(mid, node, cc, ap) and sc = mid.getSummaryCtx()
 }
 
-pragma[nomagic]
-private predicate pathIntoLocalStep(
-  PathNodeMid mid, Node midnode, CallContext cc, DataFlowCallable enclosing, SummaryCtx sc,
-  AccessPath ap0, Configuration conf
-) {
-  midnode = mid.getNode() and
-  cc = mid.getCallContext() and
-  conf = mid.getConfiguration() and
-  localFlowBigStep(midnode, _, _, _, conf, _) and
-  enclosing = midnode.getEnclosingCallable() and
-  sc = mid.getSummaryCtx() and
-  ap0 = mid.getAp()
-}
-
 pragma[nomagic]
 private predicate readCand(Node node1, Content f, Node node2, Configuration config) {
   readDirect(node1, f, node2) and

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl2.qll

@@ -2293,12 +2293,13 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
  * a callable is recorded by `cc`.
  */
 private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCtx sc, AccessPath ap) {
-  exists(
-    AccessPath ap0, Node midnode, Configuration conf, DataFlowCallable enclosing,
-    LocalCallContext localCC
-  |
-    pathIntoLocalStep(mid, midnode, cc, enclosing, sc, ap0, conf) and
-    localCC = getLocalCallContext(cc, enclosing)
+  exists(AccessPath ap0, Node midnode, Configuration conf, LocalCallContext localCC |
+    midnode = mid.getNode() and
+    conf = mid.getConfiguration() and
+    cc = mid.getCallContext() and
+    sc = mid.getSummaryCtx() and
+    localCC = getLocalCallContext(cc, midnode.getEnclosingCallable()) and
+    ap0 = mid.getAp()
   |
     localFlowBigStep(midnode, node, true, _, conf, localCC) and
     ap = ap0
@@ -2331,20 +2332,6 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   pathThroughCallable(mid, node, cc, ap) and sc = mid.getSummaryCtx()
 }
 
-pragma[nomagic]
-private predicate pathIntoLocalStep(
-  PathNodeMid mid, Node midnode, CallContext cc, DataFlowCallable enclosing, SummaryCtx sc,
-  AccessPath ap0, Configuration conf
-) {
-  midnode = mid.getNode() and
-  cc = mid.getCallContext() and
-  conf = mid.getConfiguration() and
-  localFlowBigStep(midnode, _, _, _, conf, _) and
-  enclosing = midnode.getEnclosingCallable() and
-  sc = mid.getSummaryCtx() and
-  ap0 = mid.getAp()
-}
-
 pragma[nomagic]
 private predicate readCand(Node node1, Content f, Node node2, Configuration config) {
   readDirect(node1, f, node2) and

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl3.qll

@@ -2293,12 +2293,13 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
  * a callable is recorded by `cc`.
  */
 private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCtx sc, AccessPath ap) {
-  exists(
-    AccessPath ap0, Node midnode, Configuration conf, DataFlowCallable enclosing,
-    LocalCallContext localCC
-  |
-    pathIntoLocalStep(mid, midnode, cc, enclosing, sc, ap0, conf) and
-    localCC = getLocalCallContext(cc, enclosing)
+  exists(AccessPath ap0, Node midnode, Configuration conf, LocalCallContext localCC |
+    midnode = mid.getNode() and
+    conf = mid.getConfiguration() and
+    cc = mid.getCallContext() and
+    sc = mid.getSummaryCtx() and
+    localCC = getLocalCallContext(cc, midnode.getEnclosingCallable()) and
+    ap0 = mid.getAp()
   |
     localFlowBigStep(midnode, node, true, _, conf, localCC) and
     ap = ap0
@@ -2331,20 +2332,6 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   pathThroughCallable(mid, node, cc, ap) and sc = mid.getSummaryCtx()
 }
 
-pragma[nomagic]
-private predicate pathIntoLocalStep(
-  PathNodeMid mid, Node midnode, CallContext cc, DataFlowCallable enclosing, SummaryCtx sc,
-  AccessPath ap0, Configuration conf
-) {
-  midnode = mid.getNode() and
-  cc = mid.getCallContext() and
-  conf = mid.getConfiguration() and
-  localFlowBigStep(midnode, _, _, _, conf, _) and
-  enclosing = midnode.getEnclosingCallable() and
-  sc = mid.getSummaryCtx() and
-  ap0 = mid.getAp()
-}
-
 pragma[nomagic]
 private predicate readCand(Node node1, Content f, Node node2, Configuration config) {
   readDirect(node1, f, node2) and

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl4.qll

@@ -2293,12 +2293,13 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
  * a callable is recorded by `cc`.
  */
 private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCtx sc, AccessPath ap) {
-  exists(
-    AccessPath ap0, Node midnode, Configuration conf, DataFlowCallable enclosing,
-    LocalCallContext localCC
-  |
-    pathIntoLocalStep(mid, midnode, cc, enclosing, sc, ap0, conf) and
-    localCC = getLocalCallContext(cc, enclosing)
+  exists(AccessPath ap0, Node midnode, Configuration conf, LocalCallContext localCC |
+    midnode = mid.getNode() and
+    conf = mid.getConfiguration() and
+    cc = mid.getCallContext() and
+    sc = mid.getSummaryCtx() and
+    localCC = getLocalCallContext(cc, midnode.getEnclosingCallable()) and
+    ap0 = mid.getAp()
   |
     localFlowBigStep(midnode, node, true, _, conf, localCC) and
     ap = ap0
@@ -2331,20 +2332,6 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   pathThroughCallable(mid, node, cc, ap) and sc = mid.getSummaryCtx()
 }
 
-pragma[nomagic]
-private predicate pathIntoLocalStep(
-  PathNodeMid mid, Node midnode, CallContext cc, DataFlowCallable enclosing, SummaryCtx sc,
-  AccessPath ap0, Configuration conf
-) {
-  midnode = mid.getNode() and
-  cc = mid.getCallContext() and
-  conf = mid.getConfiguration() and
-  localFlowBigStep(midnode, _, _, _, conf, _) and
-  enclosing = midnode.getEnclosingCallable() and
-  sc = mid.getSummaryCtx() and
-  ap0 = mid.getAp()
-}
-
 pragma[nomagic]
 private predicate readCand(Node node1, Content f, Node node2, Configuration config) {
   readDirect(node1, f, node2) and

java/ql/src/semmle/code/java/dataflow/internal/DataFlowImpl5.qll

@@ -2293,12 +2293,13 @@ private class PathNodeSink extends PathNodeImpl, TPathNodeSink {
  * a callable is recorded by `cc`.
  */
 private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCtx sc, AccessPath ap) {
-  exists(
-    AccessPath ap0, Node midnode, Configuration conf, DataFlowCallable enclosing,
-    LocalCallContext localCC
-  |
-    pathIntoLocalStep(mid, midnode, cc, enclosing, sc, ap0, conf) and
-    localCC = getLocalCallContext(cc, enclosing)
+  exists(AccessPath ap0, Node midnode, Configuration conf, LocalCallContext localCC |
+    midnode = mid.getNode() and
+    conf = mid.getConfiguration() and
+    cc = mid.getCallContext() and
+    sc = mid.getSummaryCtx() and
+    localCC = getLocalCallContext(cc, midnode.getEnclosingCallable()) and
+    ap0 = mid.getAp()
   |
     localFlowBigStep(midnode, node, true, _, conf, localCC) and
     ap = ap0
@@ -2331,20 +2332,6 @@ private predicate pathStep(PathNodeMid mid, Node node, CallContext cc, SummaryCt
   pathThroughCallable(mid, node, cc, ap) and sc = mid.getSummaryCtx()
 }
 
-pragma[nomagic]
-private predicate pathIntoLocalStep(
-  PathNodeMid mid, Node midnode, CallContext cc, DataFlowCallable enclosing, SummaryCtx sc,
-  AccessPath ap0, Configuration conf
-) {
-  midnode = mid.getNode() and
-  cc = mid.getCallContext() and
-  conf = mid.getConfiguration() and
-  localFlowBigStep(midnode, _, _, _, conf, _) and
-  enclosing = midnode.getEnclosingCallable() and
-  sc = mid.getSummaryCtx() and
-  ap0 = mid.getAp()
-}
-
 pragma[nomagic]
 private predicate readCand(Node node1, Content f, Node node2, Configuration config) {
   readDirect(node1, f, node2) and