CXXBaseObjectRegion is like FieldRegion. Need to blast through it when
getting the base region. This makes the RemoveDeadBindings() correct.

llvm-svn: 123375
diff --git a/clang/lib/StaticAnalyzer/MemRegion.cpp b/clang/lib/StaticAnalyzer/MemRegion.cpp
index e465224..d3d72b5 100644
--- a/clang/lib/StaticAnalyzer/MemRegion.cpp
+++ b/clang/lib/StaticAnalyzer/MemRegion.cpp
@@ -770,6 +770,7 @@
       case MemRegion::ElementRegionKind:
       case MemRegion::FieldRegionKind:
       case MemRegion::ObjCIvarRegionKind:
+      case MemRegion::CXXBaseObjectRegionKind:
         R = cast<SubRegion>(R)->getSuperRegion();
         continue;
       default: