All immediates are deferred now.

Fixed inst printer so that no opsel is generated for dst reg of cmpx
16bit insts

So it matches the documentation

Fixes: SWDEV-526726

- Change InstrInfoEmitter to emit OpName as an enum class
  instead of an anonymous enum in the OpName namespace.
- This will help clearly distinguish between values that are 
  OpNames vs just operand indices and should help avoid
  bugs due to confusion between the two.
- Rename OpName::OPERAND_LAST to NUM_OPERAND_NAMES.
- Emit declaration of getOperandIdx() along with the OpName
  enum so it doesn't have to be repeated in various headers.
- Also updated AMDGPU, RISCV, and WebAssembly backends
  to conform to the new definition of OpName (mostly
  mechanical changes).

Co-authored-by: Pravin Jagtap <Pravin.Jagtap@amd.com>

This is a refinement for the existing hack. With this,
the default target will have neither wavefrontsize feature
present, unless it was explicitly specified. That is,
getWavefrontSize() == 64 no longer implies +wavefrontsize64.
getWavefrontSize() == 32 does imply +wavefrontsize32.

Continue to assume the value is 64 with no wavesize feature.
This maintains the codegenable property without any code
that directly cares about the wavesize needing to worry about it.

Introduce an isWaveSizeKnown helper to check if we know the
wavesize is accurate based on having one of the features explicitly
set, or a known target-cpu.

I'm not sure what's going on in wave_any.s. It's testing what
happens when both wavesizes are enabled, but this is treated
as an error in codegen. We now treat wave32 as the winning
case, so some cases that were previously printed as vcc are now
vcc_lo.

Fix coding errors found by inspection and check that the swz bit still
serves to prevent merging of buffer loads/stores on GFX12+.

Identified with misc-include-cleaner.