i386: Remove workaround for Solaris ld 64-bit TLS IE limitation

i386: Remove workaround for Solaris ld 64-bit TLS IE limitation

As detailed in PR target/43309, the Solaris linker initially took the
64-bit x86 TLS IE code sequence literally, assuming that the spec only
allowed %rax as target register.

A workaround has been in place for more than a decade, but is no longer
necessary.  The bug had already been fixed for Solaris 11.1, while trunk
requires Solaris 11.4.

Uros pointed this out and suggested the attached patch.

Bootstrapped without regressions on i386-pc-solaris2.11.

2024-10-15  Uros Bizjak  <ubizjak@gmail.com>

	gcc:
	* config/i386/i386.cc (legitimize_tls_address)
	<TLS_MODEL_INITIAL_EXEC>: Remove 64-bit Solaris ld workaround.
	* config/i386/i386.md (UNSPEC_TLS_IE_SUN): Remove.
	(tls_initial_exec_64_sun): Remove.