[NVPTX] Expose float tys min, max, abs, neg as builtins

Adds support for the following builtins:

abs, neg:
- .bf16,
- .bf16x2
min, max
- {.ftz}{.NaN}{.xorsign.abs}.f16
- {.ftz}{.NaN}{.xorsign.abs}.f16x2
- {.NaN}{.xorsign.abs}.bf16
- {.NaN}{.xorsign.abs}.bf16x2
- {.ftz}{.NaN}{.xorsign.abs}.f32

Differential Revision: https://reviews.llvm.org/D117887