Fix unwinding issues when pfe is enabled.

Fix unwinding issues when pfe is enabled.

This patch has basically the same behaviour as 3dcea658c, but avoid
relying on the backend and CET mechanisms which are not implemented in
gcc-7.

gcc/ChangeLog
2021-10-18  Michael Matz  <matz@suse.de>

	* final.c (get_some_local_dynamic_name): Call
	emit_patchable_function_entry.
	* varasm.c (emit_patchable_function_entry): New.

gcc/testsuite/ChangeLog
2021-10-18  Giuliano Belinassi  <gbelinassi@suse.de>

	Backport from mainline
	2020-02-03  H.J. Lu  <hjl.tools@gmail.com>

	PR target/93492
	* gcc.target/i386/pr93492-1.c: New test.
	* gcc.target/i386/pr93492-2.c: Likewise.
	* gcc.target/i386/pr93492-3.c: Likewise.
	* gcc.target/i386/pr93492-4.c: Likewise.
	* gcc.target/i386/pr93492-5.c: Likewise.

Authored-by: Michael Matz <matz@suse.de>