Improve ARM assembly parser diagnostic for unexpected tokens.

Consider:
  mov r8, r11 fred

Previously, we issued the not very informative:
x.s:6:1: error: unexpected token in argument list

^

Now we generate:
x.s:5:14: error: unexpected token in argument list
  mov r8, r11 fred
              ^


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141380 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 355bb98..460855b 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -3617,8 +3617,9 @@
   }
 
   if (getLexer().isNot(AsmToken::EndOfStatement)) {
+    SMLoc Loc = getLexer().getLoc();
     Parser.EatToEndOfStatement();
-    return TokError("unexpected token in argument list");
+    return Error(Loc, "unexpected token in argument list");
   }
 
   Parser.Lex(); // Consume the EndOfStatement