[analyzer] Remove memoization from RunLoopAutoreleaseLeakChecker

Memoization dose not seem to be necessary, as other statement visitors
run just fine without it,
and in fact seems to be causing memory corruptions.
Just removing it instead of investigating the root cause.

rdar://45945002

Differential Revision: https://reviews.llvm.org/D54921

llvm-svn: 348822

clang/lib/StaticAnalyzer/Checkers/RunLoopAutoreleaseLeakChecker.cpp

@@ -58,13 +58,12 @@ public:
 
 } // end anonymous namespace
 
-
-using TriBoolTy = Optional<bool>;
-using MemoizationMapTy = llvm::DenseMap<const Stmt *, Optional<TriBoolTy>>;
-
-static TriBoolTy
-seenBeforeRec(const Stmt *Parent, const Stmt *A, const Stmt *B,
-              MemoizationMapTy &Memoization) {
+/// \return Whether {@code A} occurs before {@code B} in traversal of
+/// {@code Parent}.
+/// Conceptually a very incomplete/unsound approximation of happens-before
+/// relationship (A is likely to be evaluated before B),
+/// but useful enough in this case.
+static bool seenBefore(const Stmt *Parent, const Stmt *A, const Stmt *B) {
   for (const Stmt *C : Parent->children()) {
     if (!C) continue;
 
@@ -74,26 +73,9 @@ seenBeforeRec(const Stmt *Parent, const Stmt *A, const Stmt *B,
     if (C == B)
       return false;
 
-    Optional<TriBoolTy> &Cached = Memoization[C];
-    if (!Cached)
-      Cached = seenBeforeRec(C, A, B, Memoization);
-
-    if (Cached->hasValue())
-      return Cached->getValue();
+    return seenBefore(C, A, B);
   }
-
-  return None;
-}
-
-/// \return Whether {@code A} occurs before {@code B} in traversal of
-/// {@code Parent}.
-/// Conceptually a very incomplete/unsound approximation of happens-before
-/// relationship (A is likely to be evaluated before B),
-/// but useful enough in this case.
-static bool seenBefore(const Stmt *Parent, const Stmt *A, const Stmt *B) {
-  MemoizationMapTy Memoization;
-  TriBoolTy Val = seenBeforeRec(Parent, A, B, Memoization);
-  return Val.getValue();
+  return false;
 }
 
 static void emitDiagnostics(BoundNodes &Match,