Adjust C++11/C++14 tests to work with -fchar8_t

Adjust C++11/C++14 tests to work with -fchar8_t

	* testsuite/21_strings/basic_string/literals/types.cc
	[_GLIBCXX_USE_CHAR8_T]: Adjust expected string type for u8 literal.
	* testsuite/21_strings/basic_string/literals/values.cc
	[_GLIBCXX_USE_CHAR8_T]: Likewise.
	* testsuite/22_locale/codecvt/char16_t.cc: Adjust for u8 literals
	potentially having different type.
	* testsuite/22_locale/codecvt/char32_t.cc: Likewise.
	* testsuite/22_locale/codecvt/codecvt_utf8/79980.cc: Cast u8 literal
	to char.
	* testsuite/22_locale/codecvt/codecvt_utf8/wchar_t/1.cc: Likewise.
	* testsuite/22_locale/codecvt/utf8.cc: Likewise.
	* testsuite/22_locale/conversions/string/2.cc: Remove u8 prefix from
	string literals only using basic character set.
	* testsuite/22_locale/conversions/string/3.cc: Likewise. Cast other
	u8 literals to char.
	* testsuite/29_atomics/headers/atomic/macros.cc [_GLIBCXX_USE_CHAR8_T]:
	Test ATOMIC_CHAR8_T_LOCK_FREE.
	Add missing #error to ATOMIC_CHAR16_T_LOCK_FREE test.
	* testsuite/29_atomics/headers/atomic/types_std_c++0x.cc
	[_GLIBCXX_USE_CHAR8_T]: Check for std::atomic_char8_t.
	* testsuite/experimental/string_view/literals/types.cc
	[_GLIBCXX_USE_CHAR8_T]: Adjust expected string_view type for u8
	literal.
	* testsuite/experimental/string_view/literals/values.cc
	[_GLIBCXX_USE_CHAR8_T]: Likewise.

From-SVN: r269006