* include/bits/regex_compiler.h
	(_BracketMatcher<>::_M_add_equivalence_class): Implement it correctly.
	* include/bits/regex_compiler.tcc (_BracketMatcher<>::operator()):
	Add _M_equiv_set support.
	* testsuite/28_regex/algorithms/regex_match/extended/
	cstring_bracket_01.cc: Add new "[[=a=]]" testcase.

From-SVN: r203117