Sparc: use is_end_of_stmt()

... instead of open-coding it. This also fixes two array underrun
issues, when plain char is a signed type.
diff --git a/gas/config/tc-sparc.c b/gas/config/tc-sparc.c
index a22efbf..e303169 100644
--- a/gas/config/tc-sparc.c
+++ b/gas/config/tc-sparc.c
@@ -4450,7 +4450,7 @@
 static void
 s_proc (int ignore ATTRIBUTE_UNUSED)
 {
-  while (!is_end_of_line[(unsigned char) *input_line_pointer])
+  while (!is_end_of_stmt (*input_line_pointer))
     {
       ++input_line_pointer;
     }
@@ -4817,7 +4817,7 @@
 	      char *end = ++input_line_pointer;
 	      int npar = 0;
 
-	      while (! is_end_of_line[(c = *end)])
+	      while (! is_end_of_stmt (c = *end))
 		{
 		  if (c == '(')
 	  	    npar++;
@@ -4848,7 +4848,7 @@
 		      input_line_pointer++;
 		      SKIP_WHITESPACE ();
 		      c = *input_line_pointer;
-		      if (! is_end_of_line[c] && c != ',')
+		      if (! is_end_of_stmt (c) && c != ',')
 			as_bad (_("Illegal operands: garbage after %%r_%s%d()"),
 			        sparc_cons_special_reloc, size * 8);
 		    }