[libc] [llvm] [libc] Remove direct math.h includes from src (PR #84991)

[Nick Desaulniers via llvm-commits]

https://github.com/nickdesaulniers commented:

Mind removing the newlines separating this include from the previous blocks of includes, then sorting the result?

For example:
- libc/src/__support/FPUtil/FEnvImpl.h
- libc/src/__support/FPUtil/ManipulationFunctions.h
- libc/src/__support/FPUtil/NearestIntegerOperations.h
- libc/src/math/generic/math_utils.h

now all have unnecessary newlines before the inclusion of math-macros.h.

https://github.com/llvm/llvm-project/pull/84991