gdb/

gdb/
	* infcall.c (value_arg_coerce): Use value_cast_pointers for
	references.  Avoid value_cast to a reference type.  Don't silently
	convert pointers to references.
	* valops.c (value_cast_pointers): New, based on value_cast.
	(value_cast): Use it.  Reject reference types.
	(value_ref): New.
	(typecmp): Use it.
	* value.h (value_cast_pointers, value_ref): New prototypes.
gdb/testsuite/
	* gdb.cp/ref-params.exp: New test.
	* gdb.cp/ref-params.cc: New source file.
	* gdb.cp/Makefile.in (EXECUTABLES): Add ref-params.