[llvm] [test] Disable makeAllowedFCmpRegion due to taking too long (PR #111056)

[via llvm-commits]

vporpo wrote:

> I have sped up the test run from 30.22s -> 10.59s by ignoring the payload in NaN values. Is it acceptable?

What about the debug build? If it is 3 times faster, it would still be more than 2 and a half minutes, which is still too long.

https://github.com/llvm/llvm-project/pull/111056