[libc][math] Refactor copysign family to header-only (#182137)
Refactors the copysign math family to be header-only.
Closes https://github.com/llvm/llvm-project/issues/182136
Target Functions:
- copysign
- copysignbf16
- copysignf
- copysignf128
- copysignf16
- copysignl
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Co-authored-by: bassiounix <muhammad.m.bassiouni@gmail.com>