libstdc++: Fix -Wsystem-headers warnings in tests

libstdc++-v3/ChangeLog:

	* testsuite/18_support/new_nothrow.cc: Add missing noexcept
	to operator delete replacements.
	* testsuite/20_util/any/cons/92156.cc: Disable
	-Winit-list-lifetime warnings from instantiating invalid
	specialization of manager function.
	* testsuite/20_util/any/modifiers/92156.cc: Likewise.
	* testsuite/20_util/default_delete/void_neg.cc: Prune additional
	diagnostics.
	* testsuite/20_util/headers/memory/synopsis.cc: Add missing
	noexcept.
	* testsuite/20_util/shared_ptr/cons/void_neg.cc: Prune
	additional diagnostic.
	* testsuite/20_util/unique_ptr/creation/for_overwrite.cc: Add
	missing noexcept to operator delete replacements.
	* testsuite/21_strings/basic_string/cons/char/103919.cc:
	Likewise.
	* testsuite/23_containers/map/modifiers/emplace/92300.cc:
	Likewise.
	* testsuite/23_containers/map/modifiers/insert/92300.cc:
	Likewise.
	* testsuite/24_iterators/headers/iterator/range_access_c++11.cc:
	Add missing noexcept to synopsis declarations.
	* testsuite/24_iterators/headers/iterator/range_access_c++14.cc:
	Likewise.
	* testsuite/24_iterators/headers/iterator/range_access_c++17.cc:
	Likewise.