[GlobalISel] Introduce InlineAsmLowering class
Summary:
Similar to the CallLowering class used for lowering LLVM IR calls to MIR calls,
we introduce a separate class for lowering LLVM IR inline asm to MIR INLINEASM.
There is no functional change yet, all existing tests should pass.
Reviewers: arsenm, dsanders, aemerson, volkan, t.p.northover, paquette
Reviewed By: aemerson
Subscribers: gargaroff, wdng, mgorny, rovka, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78316