Fix single-line optimization for ObjC.

Puts blocks always into multiple lines when they start with an ObjC
keyword or minus.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172238 91177308-0d34-0410-b5e6-96231b3b80d8
Fix crashes in UnwrappedLineParser on missing parens.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172239 91177308-0d34-0410-b5e6-96231b3b80d8
libclang: use getCursorTU and getCursorASTUnit instead of explicit casts


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172241 91177308-0d34-0410-b5e6-96231b3b80d8
Improve diagnostic per Richard's suggestion
(which may yet change if we move the diagnostic
 outside case value).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172242 91177308-0d34-0410-b5e6-96231b3b80d8
Reject incompatible redeclarations of extern C symbols.

Before we were only checking if the new declaration itself was marked extern
C. Fixes prpr14766.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172243 91177308-0d34-0410-b5e6-96231b3b80d8