[MLIR][SPIRV] Add rewrite pattern to convert select+cmp into GLSL clamp.

Adds rewrite patterns to convert select+cmp instructions into clamp
instructions whenever possible. Support is added to convert:

- FOrdLessThan, FOrdLessThanEqual to GLSLFClampOp.
- SLessThan, SLessThanEqual to GLSLSClampOp.
- ULessThan, ULessThanEqual to GLSLUClampOp.

Reviewed By: mravishankar

Differential Revision: https://reviews.llvm.org/D93618