Revert "[libc][math][c23] Add remaining linux/* entrypoints for {,u}fromfp{,x}* (#86692)"

This reverts commit cd17082b24079a31eff0057abe407da5cfb7b0fc because the newly
added tests fail on 32b ARM.

Link: #86692
Link: https://lab.llvm.org/buildbot/#/builders/229/builds/24458
GitOrigin-RevId: 8a071678a9091d536eae29912ca7be6238105956
4 files changed