[libclc] libclc: Replace nextafter implementation (PR #186082)

[Matt Arsenault via cfe-commits]

arsenm wrote:

> ERROR: nextafter: -6988429.000000 ulp error at {0x1.aa8a34p-127 (0x6aa28d), 0x1.a0ca88p-9 (0x3b506544)}: *0x1.aa8a38p-127 vs. 0x1p-149 (0x00000001) at index: 70

This looks like the platform is inconsistent on reporting whether DAZ is enabled or not. It's returning the correct DAZ result, but expecting the non-DAZ result.

https://github.com/llvm/llvm-project/pull/186082