i386: Remove declaration of unused functions

i386: Remove declaration of unused functions

The patch fixes the issue introduced in
https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=63512c72df09b43d56ac7680cdfd57a66d40c636
and reported at
https://gcc.gnu.org/pipermail/gcc-patches/2024-June/655599.html .

Regards,
Evgeny

The patch fixes the issue with compilation on x86_64-gnu-linux
when warnings for unused functions are treated as errors.

gcc/ChangeLog:

	* config/i386/i386.cc (legitimize_dllimport_symbol): Remove unused
	functions.
	(legitimize_pe_coff_extern_decl): Likewise.