hardened conditionals: drop copied identifiers

The copies of identifiers, indended to associate hardening SSA
temporaries to the original variables they refer to, end up causing
-fcompare-debug to fail, because DECL_UIDs are not identical, and the
nouid flag used in compare-debug dumps doesn't affect the uids in
naked identifiers, so the divergence becomes apparent.

This patch drops the naked identifiers.  Though somewhat desirable,
they're not necessary.


for  gcc/ChangeLog

	PR debug/104564
	* gimple-harden-conditionals.cc (detach_value): Keep temps
	anonymous.

for  gcc/testsuite/ChangeLog

	PR debug/104564
	* c-c++-common/torture/harden-comp.c: Adjust.
	* c-c++-common/torture/harden-cond.c: Adjust.