Change references to 'const ProgramState *' to typedef 'ProgramStateRef'.

At this point this is largely cosmetic, but it opens the door to replace
ProgramStateRef with a smart pointer that more eagerly acts in the role
of reclaiming unused ProgramState objects.

llvm-svn: 149081
diff --git a/clang/lib/StaticAnalyzer/Checkers/PointerSubChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/PointerSubChecker.cpp
index 51f57a2..e6d25fd 100644
--- a/clang/lib/StaticAnalyzer/Checkers/PointerSubChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/PointerSubChecker.cpp
@@ -39,7 +39,7 @@
   if (B->getOpcode() != BO_Sub)
     return;
 
-  const ProgramState *state = C.getState();
+  ProgramStateRef state = C.getState();
   const LocationContext *LCtx = C.getLocationContext();
   SVal LV = state->getSVal(B->getLHS(), LCtx);
   SVal RV = state->getSVal(B->getRHS(), LCtx);