MC intel asm parser: Allow @ at the start of function names.

Ports parts of r193000 to the intel parser. Fixes part of PR36676.

https://reviews.llvm.org/D44359


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327262 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed