Add missing noexcept on definition to match declaration

	* include/bits/regex.tcc (regex_iterator::operator==): Add missing
	noexcept.

From-SVN: r262146

libstdc++-v3/ChangeLog

+2018-06-26  Jonathan Wakely  <jwakely@redhat.com>
+
+	* include/bits/regex.tcc (regex_iterator::operator==): Add missing
+	noexcept.
+
 2018-06-25  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/86112

libstdc++-v3/include/bits/regex.tcc

@@ -500,7 +500,7 @@ namespace __detail
 	   typename _Rx_traits>
     bool
     regex_iterator<_Bi_iter, _Ch_type, _Rx_traits>::
-    operator==(const regex_iterator& __rhs) const
+    operator==(const regex_iterator& __rhs) const noexcept
     {
       if (_M_pregex == nullptr && __rhs._M_pregex == nullptr)
 	return true;