Implement jump checking for initialized c++ variables, implementing
a fixme and PR6451.

Only perform jump checking if the containing function has no errors,
and add the infrastructure needed to do this.

On the testcase in the PR, we produce:

t.cc:6:3: error: illegal goto into protected scope
  goto later;
  ^
t.cc:7:5: note: jump bypasses variable initialization
  X x;
    ^



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97497 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 939ccab..0ec7933 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -50,6 +50,7 @@
     return;
 
   CurFunctionNeedsScopeChecking = false;
+  NumErrorsAtStartOfFunction = getDiagnostics().getNumErrors();
 
   // Allow the rest of sema to find private method decl implementations.
   if (MDecl->isInstanceMethod())