ipa-visibility: Optimize TLS access [PR99619]

ipa-visibility: Optimize TLS access [PR99619]

Fix PR99619, which asks to optimize TLS model based on visibility.
The fix is implemented as an IPA optimization: this allows to take
optimized visibility status into account (as well as avoid modifying
all language frontends).

2022-04-17  Artem Klimov  <jakmobius@gmail.com>

gcc/ChangeLog:

	PR middle-end/99619
	* ipa-visibility.cc (function_and_variable_visibility): Promote
	TLS access model afer visibility optimizations.
	* varasm.cc (have_optimized_refs): New helper.
	(optimize_dyn_tls_for_decl_p): New helper. Use it ...
	(decl_default_tls_model): ... here in place of 'optimize' check.

gcc/testsuite/ChangeLog:

	PR middle-end/99619
	* gcc.dg/tls/vis-attr-gd.c: New test.
	* gcc.dg/tls/vis-attr-hidden-gd.c: New test.
	* gcc.dg/tls/vis-attr-hidden.c: New test.
	* gcc.dg/tls/vis-flag-hidden-gd.c: New test.
	* gcc.dg/tls/vis-flag-hidden.c: New test.
	* gcc.dg/tls/vis-pragma-hidden-gd.c: New test.
	* gcc.dg/tls/vis-pragma-hidden.c: New test.

Co-Authored-By:  Alexander Monakov  <amonakov@gcc.gnu.org>
Signed-off-by: Artem Klimov <jakmobius@gmail.com>