Add more feature to tableGen backend gen-dxil-operation.
It will generate getOpCodeProperty, getOpCodeClassName and getOpCodeName when build DirectX target.
Each of these functions has a table which generate based on DXIL operations.
These generated functions will replace the manually written functions which used for query DXIL operation information.
Unused variable here, broke the sanitizer build bots that build with -Werror.