Add clarifying comment.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164557 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/AnalysisDeclContext.cpp

@@ -218,6 +218,8 @@ PseudoConstantAnalysis *AnalysisDeclContext::getPseudoConstantAnalysis() {
 
 AnalysisDeclContext *AnalysisDeclContextManager::getContext(const Decl *D) {
   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+    // Calling 'hasBody' replaces 'FD' in place with the FunctionDecl
+    // that has the body.
     FD->hasBody(FD);
     D = FD;
   }