C++: Fix PR86082

C++: Fix PR86082

When turning a user-defined numerical literal into an operator
invocation the literal needs to be translated to the execution
character set.

gcc/cp/ChangeLog:

2018-06-25  Andreas Krebbel  <krebbel@linux.ibm.com>

	PR C++/86082
	* parser.c (make_char_string_pack): Pass this literal chars
	through cpp_interpret_string.
	(cp_parser_userdef_numeric_literal): Check the result of
	make_char_string_pack.

gcc/testsuite/ChangeLog:

2018-06-25  Andreas Krebbel  <krebbel@linux.ibm.com>

	PR C++/86082
	* g++.dg/pr86082.C: New test.

From-SVN: r262003