[analyzer] Resolve another bug where the name of the leaked object was not printed properly

[NoQ]

Thx!

lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountDiagnostics.cpp

while (N) {
     if (!getRefBinding(St, Sym))
       break;
 
     StoreManager::FindUniqueBinding FB(Sym);
     StateMgr.iterBindings(St, FB);
 
     if (FB) {
       const MemRegion *R = FB.getRegion();
-      const VarRegion *VR = R->getBaseRegion()->getAs<VarRegion>();
       // Do not show local variables belonging to a function other than
       // where the error is reported.
-      if (!VR || VR->getStackFrame() == LeakContext->getStackFrame())
+      if (auto MR = dyn_cast<StackSpaceRegion>(R->getMemorySpace()))
+        if (MR->getStackFrame() == LeakContext->getStackFrame())
           FirstBinding = R;
     }
 
     // AllocationNode is the last node in which the symbol was tracked.
     AllocationNode = N;
 
     // AllocationNodeInCurrentContext, is the last node in the current or
     // parent context in which the symbol was tracked.
     //

test/Analysis/osobject-retain-release.cpp

void check_free_use_after_free() {
   arr->retain(); // expected-note{{Reference count incremented. The object now has a +2 retain count}}
   arr->free(); // expected-note{{Object released}}
   arr->retain(); // expected-warning{{Reference-counted object is used after it is released}}
                  // expected-note@-1{{Reference-counted object is used after it is released}}
 }
 
 unsigned int check_leak_explicit_new() {
   OSArray *arr = new OSArray; // expected-note{{Operator new returns an OSObject of type OSArray with a +1 retain count}}
-  return arr->getCount(); // expected-note{{Object leaked: allocated object of type OSArray is not referenced later in this execution path and has a retain count of +1}}
-                          // expected-warning@-1{{Potential leak of an object of type OSArray}}
+  return arr->getCount(); // expected-note{{Object leaked: object allocated and stored into 'arr' is not referenced later in this execution path and has a retain count of +1}}
+                          // expected-warning@-1{{Potential leak of an object stored into 'arr'}}
 }
 
 unsigned int check_leak_factory() {
   OSArray *arr = OSArray::withCapacity(10); // expected-note{{Call to method 'OSArray::withCapacity' returns an OSObject of type OSArray with a +1 retain count}}
   return arr->getCount(); // expected-note{{Object leaked: object allocated and stored into 'arr' is not referenced later in this execution path and has a retain count of +1}}
                           // expected-warning@-1{{Potential leak of an object stored into 'arr'}}
 }