C++: Don't generate dataflow nodes for instructions inside summarized callables.

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaInternalsCommon.qll

@@ -41,7 +41,9 @@ predicate ignoreInstruction(Instruction instr) {
     instr instanceof AliasedUseInstruction or
     instr instanceof InitializeNonLocalInstruction or
     instr instanceof ReturnIndirectionInstruction or
-    instr instanceof UninitializedGroupInstruction
+    instr instanceof UninitializedGroupInstruction or
+    // We exclude instruction belonging to functions that have a summary.
+    instr.getEnclosingFunction() = any(SummarizedCallable sc).getUnderlyingCallable()
   )
 }