[rl78] add rtx paranoia

[DJ Delorie]

Building newlib uncovered a few invalid assumptions...  Committed.

        * config/rl78/rl78.c (rl78_alloc_address_registers_macax): Verify
        op is a REG before checking REGNO.
        (rl78_alloc_physical_registers): Verify pattern is a SET before
        checking SET_SRC.

Index: config/rl78/rl78.c
===================================================================
--- config/rl78/rl78.c  (revision 203732)
+++ config/rl78/rl78.c  (working copy)
@@ -3047,13 +3047,14 @@ rl78_alloc_address_registers_macax (rtx 
              replace_in_op0 = (op > 0 && rtx_equal_p (OP (op), OP (0)));
              replace_in_op1 = (op > 1 && rtx_equal_p (OP (op), OP (1)));
 
              OP (op) = transcode_memory_rtx (OP (op), HL, insn);
              if (op == 2
                  && MEM_P (OP (op))
-                 && (REGNO (XEXP (OP (op), 0)) == SP_REG
+                 && ((GET_CODE (XEXP (OP (op), 0)) == REG
+                      && REGNO (XEXP (OP (op), 0)) == SP_REG)
                      || (GET_CODE (XEXP (OP (op), 0)) == PLUS
                          && REGNO (XEXP (XEXP (OP (op), 0), 0)) == SP_REG)))
                {
                  emit_insn_before (gen_movhi (HL, gen_rtx_REG (HImode, 
SP_REG)), insn);
                  OP (op) = replace_rtx (OP (op), gen_rtx_REG (HImode, SP_REG), 
HL);
                }
@@ -3137,13 +3138,14 @@ rl78_alloc_physical_registers (void)
        pattern = XVECEXP (pattern, 0, 0);
       if (JUMP_P (insn) || CALL_P (insn) || GET_CODE (pattern) == CALL)
        clear_content_memory ();
       if (GET_CODE (pattern) != SET
          && GET_CODE (pattern) != CALL)
        continue;
-      if (GET_CODE (SET_SRC (pattern)) == ASM_OPERANDS)
+      if (GET_CODE (pattern) == SET
+         && GET_CODE (SET_SRC (pattern)) == ASM_OPERANDS)
        continue;
 
       valloc_method = get_attr_valloc (insn);
 
       PATTERN (insn) = copy_rtx_if_shared (PATTERN (insn));