[Xtensa Patch] Report error on certain opcode expressions with syntax errors

[Sterling Augustine]

The Xtensa opcode argument parsing code was missing certain unusual 
errors where there was a valid expression immediately followed by a 
syntax error, such as

movi a2, 1syntax_error

This small patch adds code to catch those errors.

Tested on xtensa-unknown-elf mainline.

Sterling

Index: gas/config/tc-xtensa.c
===================================================================
--- gas/config/tc-xtensa.c	7 Jan 2009 17:41:09 -0000	1.108
+++ gas/config/tc-xtensa.c	1 Apr 2009 20:56:40 -0000
@@ -2046,6 +2046,7 @@ parse_arguments (TInsn *insn, int num_ar

  	  last_tok = tok;
  	  last_opnd_cnt = opnd_cnt;
+	  demand_empty_rest_of_line ();

  	  do
  	    {