libgcc: Export i386 symbols added after GCC_7.0.0 on Solaris [PR113700]

As reported in the PR, all libgcc x86 symbol versions added after
GCC_7.0.0 were only added to i386/libgcc-glibc.ver, missing all of
libgcc-sol2.ver, libgcc-bsd.ver, and libgcc-darwin.ver.

This patch fixes this for Solaris/x86, adding all of them
(GCC_1[234].0.0) as GCC_14.0.0 to not retroactively change history.

Since this isn't the first time this happens, I've added a note to the
end of libgcc-glibc.ver to request notifying other maintainers in case
of additions.

Tested on i386-pc-solaris2.11.

2024-02-01  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	libgcc:
	PR target/113700
	* config/i386/libgcc-sol2.ver (GCC_14.0.0): Added all symbols from
	i386/libgcc-glibc.ver (GCC_12.0.0, GCC_13.0.0, GCC_14.0.0).
	* config/i386/libgcc-glibc.ver: Request notifications on updates.