[llvm-branch-commits] [DirectX] Make DXILOpBuilder's API more useable (PR #101250)

[Justin Bogner via llvm-branch-commits]

https://github.com/bogner created https://github.com/llvm/llvm-project/pull/101250

This adjusts the DXILOpBuilder API in a couple of ways:
1. Remove the need to call `getOverloadTy` before creating Ops
2. Introduce `tryCreateOp` to parallel `createOp` but propagate errors
3. Introduce specialized createOp methods for each DXIL Op

This will simplify usage of the builder in upcoming changes, and also allows us
to propagate errors via DiagnosticInfo rather than using fatal errors.