* cgen.c: #include setjmp.h. Clean up pass over `struct foo' usage.

	* cgen.c: #include setjmp.h.  Clean up pass over `struct foo' usage.
	(expr_jmp_buf): New static local.
	(cgen_parse_operand): Allow use of longjmp in parsing to handle errors.
	(cgen_md_operand): New function.
	* tc-m32r.c: Clean up pass over `struct foo' usage.
	(md_estimate_size_before_relax): Use CGEN_INSN_MNEMONIC.