Update to use enum classes for various ARM *Kind enums

Summary: This updates the relevant Clang parts for the LLVM change D35882.

Reviewers: rengolin, chandlerc, javed.absar, rovka

Reviewed By: rovka

Subscribers: aemerson, cfe-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D35884

llvm-svn: 309289