Add a utility method.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@96471 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/AnalysisContext.cpp b/lib/Analysis/AnalysisContext.cpp
index ccd5088..d9933e8 100644
--- a/lib/Analysis/AnalysisContext.cpp
+++ b/lib/Analysis/AnalysisContext.cpp
@@ -186,6 +186,18 @@
   return NULL;
 }
 
+bool LocationContext::isParentOf(const LocationContext *LC) const {
+  do {
+    const LocationContext *Parent = LC->getParent();
+    if (Parent == this)
+      return true;
+    else
+      LC = Parent;
+  } while (LC);
+
+  return false;
+}
+
 //===----------------------------------------------------------------------===//
 // Lazily generated map to query the external variables referenced by a Block.
 //===----------------------------------------------------------------------===//