[libclang] Add attribute support for 'convergent'.

This bumps CINDEX_VERSION_MINOR up (to 51).

Patch by Hsin-Hsiao Lin.

Differential Revision: https://reviews.llvm.org/D57946

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@353690 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed