Java: Consolidate Assertions.qll and Preconditions.qll.

java/ql/lib/semmle/code/java/ControlFlowGraph.qll

@@ -365,10 +365,10 @@ private module ControlFlowGraphImpl {
    * Bind `t` to an unchecked exception that may occur in a precondition check or guard wrapper.
    */
   private predicate uncheckedExceptionFromMethod(MethodCall ma, ThrowableType t) {
-    conditionCheckArgument(ma, _, _) and
+    (methodCallChecksArgument(ma) or methodCallUnconditionallyThrows(ma)) and
     (t instanceof TypeError or t instanceof TypeRuntimeException)
     or
-    methodMayThrow(ma.getMethod(), t)
+    methodMayThrow(ma.getMethod().getSourceDeclaration(), t)
   }
 
   /**
@@ -586,6 +586,7 @@ private module ControlFlowGraphImpl {
    * Gets a `MethodCall` that always throws an exception or calls `exit`.
    */
   private MethodCall nonReturningMethodCall() {
+    methodCallUnconditionallyThrows(result) or
     result.getMethod().getSourceDeclaration() = nonReturningMethod() or
     result = likelyNonReturningMethod().getAnAccess()
   }