Summary:
Change MCExpr to support Aurora VE's modifiers. Change asmparser to use
existing MCExpr parser (parseExpression) to parse an expression contining
symbols with modifiers and offsets. Also add several regression tests
of MC layer.
Reviewers: simoll, k-ishizaka
Reviewed By: simoll
Subscribers: hiraditya, llvm-commits
Tags: #llvm, #ve
Differential Revision: https://reviews.llvm.org/D83170
475cbdd9be