[WebAssembly] Modified tablegen defs to have 2 parallel instuction sets.
One for register based, much like the existing definitions,
and one for stack based (suffix _S).
This allows us to use registers in most of LLVM (which works better),
and stack based in MC (which results in a simpler and more readable
assembler / disassembler).
Tried to keep this change as small as possible while passing tests,
follow-up commit will:
- Add reg->stack conversion in MI.
- Fix asm/disasm in MC to be stack based.
- Fix emitter to be stack based.
llvm-lit -v find test -name WebAssembly
Reviewers: dschuff, sbc100, jgravelle-google, sunfish
Subscribers: aheejin, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D48183