Fix problematic TLS sequences for the Solaris linker

Fix problematic TLS sequences for the Solaris linker

This is an old thinko pertaining to the interaction between TLS
sequences and delay slot filling: the compiler knows that it cannot
put instructions with TLS relocations into delay slots with the
original Sun TLS model, but it tests TARGET_SUN_TLS in this context,
which depends only on the assembler.  So if the compiler is configured
with the GNU assembler and the Solaris linker, then TARGET_GNU_TLS is
set instead and the limitation is not enforced.

	PR target/93704
	* config/sparc/sparc.c (eligible_for_call_delay): Test HAVE_GNU_LD
	in conjunction with TARGET_GNU_TLS in early return.