math: Remove the SVID error handling from remainderf

math: Remove the SVID error handling from remainderf

The optimized i386 version is faster than the generic one, and gcc
implements it through the builtin.  This optimization enables us to
migrate the implementation to a C version.  The performance on a Zen3
chip is similar to the SVID one.

The m68k provided an optimized version through __m81_u(remainderf)
(mathimpl.h), and gcc does not implement it through a builtin (different
than i386).

Performance improves a bit on x86_64 (Zen3, gcc 15.2.1):

reciprocal-throughput          input   master  NO-SVID  improvement
x86_64                    subnormals  17.5349  15.6125       10.96%
x86_64                        normal  53.8134  52.5754        2.30%
x86_64                close-exponent  20.0211  18.6656        6.77%
i686                      subnormals  21.8105  20.1856        7.45%
i686                          normal  73.1945  71.2199        2.70%
i686                  close-exponent  22.2141   20.331        8.48%

Tested on x86_64-linux-gnu and i686-linux-gnu.

Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>