* regex_executor.h(_M_handle_repeat, _M_handle_subexpr_begin)
	(_M_handle_subexpr_end, _M_handle_line_begin_assertion)
	(_M_handle_line_end_assertion, _M_handle_word_boundary)
	(_M_handle_subexpr_lookahead, _M_handle_match)
	(_M_handle_backref, _M_handle_accept, _M_handle_alternative):
	Add separate function declarations.
	* regex_executor.tcc: Split _M_dfs() into multiple handler functions.

From-SVN: r239673