[libc][math] Refactor dsub Math Functions to Header Only

[hulxv]

This is tracking issue to refactor dsub math functions currently implemented in LLVM libc to be header-only.

part of: #147386

Target Functions:

• dsubf128
• dsubl

CC: @bassiounix

[llvmbot]

@llvm/issue-subscribers-libc

Author: Mohamed Emad (hulxv)

Details

This is tracking issue to refactor dsub math functions currently implemented in LLVM libc to be header-only.

part of: #147386

Target Functions:

• dsubf128
• dsubl

CC: @bassiounix