c++: ICE with noexcept in class in member function [PR96623]

c++: ICE with noexcept in class in member function [PR96623]

I discovered very strange code in inject_parm_decls:

   if (args && is_this_parameter (args))
     {
       gcc_checking_assert (current_class_ptr == NULL_TREE);
       current_class_ptr = NULL_TREE;

We are tripping up on the assert because when we call inject_parm_decls,
current_class_ptr is set to 'A'.  It was set by inject_this_parameter
after we've parsed the parameter-declaration-clause of the member
function foo.  It seems correct to set ccp/ccr to A::B when we're
late parsing the noexcept-specifiers of bar* functions in B, so that
this-> does the right thing.  Since inject_parm_decls doesn't expect
to see non-null ccp/ccr, reset it before calling inject_parm_decls.

gcc/cp/ChangeLog:

	PR c++/96623
	* parser.c (inject_parm_decls): Remove a redundant assignment.
	(cp_parser_class_specifier_1): Clear current_class_{ptr,ref}
	before calling inject_parm_decls.

gcc/testsuite/ChangeLog:

	PR c++/96623
	* g++.dg/cpp0x/noexcept64.C: New test.