Implement the no_split_stack attribute.

This is a GNU attribute that allows split stacks to be turned off on a
per-function basis.

Differential Revision: http://reviews.llvm.org/D3817

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209167 91177308-0d34-0410-b5e6-96231b3b80d8
[module] Remove a header that isn't used and doesn't compile.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209168 91177308-0d34-0410-b5e6-96231b3b80d8
[modules] Fix ODR violation: there's another clang::TypeLocVisitor elsewhere.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209169 91177308-0d34-0410-b5e6-96231b3b80d8
Fix usage of string when StringRef was needed

Also adding a variable to the test, so release bots match %1.
This should also calm the gdb buildbot.

.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209171 91177308-0d34-0410-b5e6-96231b3b80d8
Get ARCMT/GC-check-warn-nsalloc.m working

The -no-ns-alloc-error migration option now causes the diagnostic to be ignored
completely. If this isn't desired, the error can be downgraded to a warning
using the usual -Wno-error=arcmt-ns-alloc.

Note that we can't use -verify right now on this test because
VerifyDiagnosticConsumer gets confused by multiple SourceManager instances,
which is presumably the reason it was XFAILed in the first place and why the
regression wasn't detected. We'll grep instead for now.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@209172 91177308-0d34-0410-b5e6-96231b3b80d8