simplify expressions that could be type-casts

csharp/ql/lib/Linq/Helpers.qll

@@ -46,7 +46,7 @@ predicate missedAllOpportunity(ForeachStmt fes) {
       bl = a.getRValue() and
       bl.toString() = "false"
     ) and
-    exists(BreakStmt bs | bs = is.getThen().getAChild*())
+    is.getThen().getAChild*() instanceof BreakStmt
   )
 }
 

csharp/ql/lib/semmle/code/csharp/XML.qll

@@ -233,7 +233,7 @@ class XMLElement extends @xmlelement, XMLParent, XMLLocatable {
   XMLAttribute getAttribute(string name) { result.getElement() = this and result.getName() = name }
 
   /** Holds if this XML element has an attribute with the specified `name`. */
-  predicate hasAttribute(string name) { exists(XMLAttribute a | a = this.getAttribute(name)) }
+  predicate hasAttribute(string name) { exists(this.getAttribute(name)) }
 
   /** Gets the value of the attribute with the specified `name`, if any. */
   string getAttributeValue(string name) { result = this.getAttribute(name).getValue() }

csharp/ql/lib/semmle/code/csharp/dispatch/Dispatch.qll

@@ -292,7 +292,7 @@ private module Internal {
     pragma[nomagic]
     predicate hasSubsumedQualifierTypeOverridden(Gvn::GvnType t, OverridableCallable c) {
       this.hasSubsumedQualifierType(t) and
-      hasCallable(t, c, any(OverridableCallable oc | oc = this.getAStaticTargetExt()))
+      hasCallable(t, c, this.getAStaticTargetExt())
     }
 
     /**

csharp/ql/src/Likely Bugs/Statements/UseBraces.ql

@@ -26,11 +26,11 @@ Stmt getASuccessorStmt(Stmt s) {
 }
 
 class IfThenStmt extends IfStmt {
-  IfThenStmt() { not exists(Stmt s | getElse() = s) }
+  IfThenStmt() { not exists(getElse()) }
 }
 
 class IfThenElseStmt extends IfStmt {
-  IfThenElseStmt() { exists(Stmt s | getElse() = s) }
+  IfThenElseStmt() { exists(getElse()) }
 }
 
 Stmt getTrailingBody(Stmt s) {

csharp/ql/src/experimental/ir/internal/IRGuards.qll

@@ -24,7 +24,7 @@ class GuardCondition extends Expr {
     exists(IRGuardCondition ir | this = ir.getUnconvertedResultExpression())
     or
     // no binary operators in the IR
-    exists(GuardCondition gc | this.(BinaryLogicalOperation).getAnOperand() = gc)
+    this.(BinaryLogicalOperation).getAnOperand() instanceof GuardCondition
     or
     // the IR short-circuits if(!x)
     // don't produce a guard condition for `y = !x` and other non-short-circuited cases
@@ -124,7 +124,7 @@ private predicate impliesValue(
  */
 private class GuardConditionFromBinaryLogicalOperator extends GuardCondition {
   GuardConditionFromBinaryLogicalOperator() {
-    exists(GuardCondition gc | this.(BinaryLogicalOperation).getAnOperand() = gc)
+    this.(BinaryLogicalOperation).getAnOperand() instanceof GuardCondition
   }
 
   override predicate controls(BasicBlock controlled, boolean testIsTrue) {