[libclc] [libclc] Replace NVPTX libdevice calls with clang builtins for sqrt, rsqrt, isinf (PR #205709)

[Wenju He via cfe-commits]

wenju-he wrote:

to match the behavior with nv libdevice, libclc probably can call @llvm.nvvm.rsqrt.approx.ftz.f when __clc_denormals_are_zero_fp32() return true

https://github.com/llvm/llvm-project/pull/205709