[SVE][Inline-Asm] Add support to specify SVE registers in the clobber list

Adds the SVE vector and predicate registers to the list of known registers.

Patch by Kerry McLaughlin.

Reviewers: erichkeane, sdesmalen, rengolin

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D64739

llvm-svn: 366878