re PR target/6303 (output_operand: invalid expression as operand)

re PR target/6303 (output_operand: invalid expression as operand)

	PR target/6303
	* dwarf2out.c (rtl_for_decl_location): Call ASM_SIMPLIFY_DWARF_ADDR
	before returning.
	* config/i386/i386.c (i386_simplify_dwarf_addr): Simplify @GOT only
	when inside of MEM by eliminating the indirection too.
	* config/s390/s390.h (ASM_SIMPLIFY_DWARF_ADDR): Define.
	* config/s390/s390.c (s390_simplify_dwarf_addr): New.
	* config/s390/s390-protos.h (s390_simplify_dwarf_addr): Add
	prototype.

	* gcc.dg/20020415-1.c: New test.

From-SVN: r52358