Avoid -Wdangling-pointer for by-transparent-reference arguments [PR104436].

Avoid -Wdangling-pointer for by-transparent-reference arguments [PR104436].

This change avoids -Wdangling-pointer for by-value arguments transformed
into by-transparent-reference.

Resolves:
PR middle-end/104436 - spurious -Wdangling-pointer assigning local address to a class passed by value

gcc/ChangeLog:

	PR middle-end/104436
	* gimple-ssa-warn-access.cc (pass_waccess::check_dangling_stores):
	Check for warning suppression.  Avoid by-value arguments transformed
	into by-transparent-reference.

gcc/testsuite/ChangeLog:

	PR middle-end/104436
	* c-c++-common/Wdangling-pointer-8.c: New test.
	* g++.dg/warn/Wdangling-pointer-5.C: New test.