[analyzer] Handle the dot syntax for properties in the ExprEngine.

We translate property accesses to obj-c messages by simulating "loads" or "stores" to properties
using a pseudo-location SVal kind (ObjCPropRef).

Checkers can now reason about obj-c messages for both explicit message expressions and implicit
messages due to property accesses.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124161 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/BasicStore.cpp b/lib/StaticAnalyzer/BasicStore.cpp
index 42fd339..0254ba7 100644
--- a/lib/StaticAnalyzer/BasicStore.cpp
+++ b/lib/StaticAnalyzer/BasicStore.cpp
@@ -196,6 +196,7 @@
       return V.isUnknownOrUndef() ? V : CastRetrievedVal(V, TR, T);
     }
 
+    case loc::ObjCPropRefKind:
     case loc::ConcreteIntKind:
       // Support direct accesses to memory.  It's up to individual checkers
       // to flag an error.