re PR libstdc++/63775 ([C++11] Regex range with leading dash (-) not working)

	PR libstdc++/63775
	* include/bits/regex_compiler.h (_Compiler<>::_M_expression_term,
	_BracketMatcher<>::_M_make_range): Throw regex_erorr on invalid range
	like [z-a]. Change _M_expression_term interface.
	* include/bits/regex_compiler.tcc (
	_Compiler<>::_M_insert_bracket_matcher,
	_Compiler<>::_M_expression_term): Rewrite bracket expression parsing.
	* testsuite/28_regex/algorithms/regex_match/cstring_bracket_01.cc:
	Add testcases and move file out of extended.

From-SVN: r217461