MemRegion can refer to ASTContext without external help.

llvm-svn: 110784
diff --git a/clang/lib/Checker/SymbolManager.cpp b/clang/lib/Checker/SymbolManager.cpp
index 3145f40..6095fe5 100644
--- a/clang/lib/Checker/SymbolManager.cpp
+++ b/clang/lib/Checker/SymbolManager.cpp
@@ -191,7 +191,7 @@
 }
 
 QualType SymbolDerived::getType(ASTContext& Ctx) const {
-  return R->getValueType(Ctx);
+  return R->getValueType();
 }
 
 QualType SymbolExtent::getType(ASTContext& Ctx) const {
@@ -199,7 +199,7 @@
 }
 
 QualType SymbolRegionValue::getType(ASTContext& C) const {
-  return R->getValueType(C);
+  return R->getValueType();
 }
 
 SymbolManager::~SymbolManager() {}