re PR testsuite/61061 (FAIL: g++.dg/inherit/covariant7.C)

re PR testsuite/61061 (FAIL: g++.dg/inherit/covariant7.C)

	PR libstdc++/61061
	PR libstdc++/61582
	* include/bits/regex_automaton.h (_NFA<>::_M_insert_state): Add
	a NFA state limit. If it's exceeded, regex_constants::error_space
	will be throwed.
	* include/bits/regex_automaton.tcc (_StateSeq<>::_M_clone): Use
	map (which is sparse) instead of vector. This reduce n times clones'
	cost from O(n^2) to O(n).
	* include/std/regex: Add map dependency.
	* testsuite/28_regex/algorithms/regex_match/ecma/char/61601.cc: New
	testcase.

From-SVN: r212185