[mlir][spirv] Let SPIRVConversionTarget consider type availability

[antiagainst]

Summary

Previously we only consider the version/extension/capability requirement
on the op itself. This commit updates SPIRVConversionTarget to also
take into consideration the values' types when deciding op legality.

Depends On D75875

[antiagainst]

Updates

[mravishankar]

mlir/lib/Dialect/SPIRV/SPIRVLowering.cpp

414

Could we add a method that sets some targetEnv by default (the one that are used in the tests here for example).

[mravishankar]

mlir/lib/Dialect/SPIRV/SPIRVLowering.cpp

414

Just to add to this. Then we can remove the "lookupTargetEnvOrDefault" method right?

[antiagainst]

mlir/lib/Dialect/SPIRV/SPIRVLowering.cpp

414

I'd like to keep the responsibility separate. We already have three helper functions for getting the target env: getDefaultTargetEnv, lookupTargetEnv, and lookupTargetEnvOrDefault. This class should be focusing on conversion target. If one want to just use the default target env, one can use getDefaultTargetEnv to create a SPIRVConversionTarget.