[analyzer] Add getLocationContext to CheckerContext

CheckerContext::getPredecessor is only used to get to the LocationContext
half of the times.

llvm-svn: 143061
diff --git a/clang/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp
index d00ef59..4ad7cc9 100644
--- a/clang/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/BuiltinFunctionChecker.cpp
@@ -57,8 +57,7 @@
     // FIXME: Refactor into StoreManager itself?
     MemRegionManager& RM = C.getStoreManager().getRegionManager();
     const AllocaRegion* R =
-      RM.getAllocaRegion(CE, C.getCurrentBlockCount(),
-                         C.getPredecessor()->getLocationContext());
+      RM.getAllocaRegion(CE, C.getCurrentBlockCount(), C.getLocationContext());
 
     // Set the extent of the region in bytes. This enables us to use the
     // SVal of the argument directly. If we save the extent in bits, we