re PR bootstrap/63622 (Bootstrap fails on x86_64-apple-darwin1[34] after revision...

re PR bootstrap/63622 (Bootstrap fails on x86_64-apple-darwin1[34] after revision r216305)

PR ipa/63622

        PR ipa/63795
	* g++.dg/ipa/ipa-icf-4.C: Add more precise dump scan.
	* g++.dg/ipa/ipa-icf-5.C: Add condition for target
	with symbol alias support.
	* ipa-icf.c (sem_function::merge): Add new target symbol alias
	support guard.
	(sem_variable::merge): Likewise.
	* ipa-icf.h (target_supports_symbol_aliases_p): New function.

From-SVN: r217355