Keep track of objc method redeclarations in the same interface.

Avoid possible infinite loop when iterating over an ObjCMethod's redeclarations.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141946 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/DeclObjC.cpp b/lib/AST/DeclObjC.cpp
index 48fbbe0..7c1332a 100644
--- a/lib/AST/DeclObjC.cpp
+++ b/lib/AST/DeclObjC.cpp
@@ -392,7 +392,11 @@
 /// Otherwise it will return itself.
 ObjCMethodDecl *ObjCMethodDecl::getNextRedeclaration() {
   ASTContext &Ctx = getASTContext();
-  ObjCMethodDecl *Redecl = 0;
+  ObjCMethodDecl *Redecl =
+      const_cast<ObjCMethodDecl*>(Ctx.getObjCMethodRedeclaration(this));
+  if (Redecl)
+    return Redecl;
+
   Decl *CtxD = cast<Decl>(getDeclContext());
 
   if (ObjCInterfaceDecl *IFD = dyn_cast<ObjCInterfaceDecl>(CtxD)) {