rs6000: Don't forget to initialize the TOC (PR77957)

The code generating traceback tables mistakenly does an early return
if !optional_tbtab, which causes it to miss the code generating the TOC
section.  This only matters if the TOC will be empty since otherwise
the section is created elsewhere.

This patch fixes it.


	PR target/77957
	* config/rs6000/rs6000.c (rs6000_output_function_epilogue): Don't
	return early if !optional_tbtab.

From-SVN: r242336

gcc/ChangeLog

+2016-11-12  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	PR target/77957
+	* config/rs6000/rs6000.c (rs6000_output_function_epilogue): Don't
+	return early if !optional_tbtab.
+
 2016-11-11  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR rtl-optimization/59461

gcc/config/rs6000/rs6000.c

@@ -30412,17 +30412,17 @@ rs6000_output_function_epilogue (FILE *file,
 	 seems to set the bit when not optimizing.  */
       fprintf (file, "%d\n", ((float_parms << 1) | (! optimize)));
 
-      if (! optional_tbtab)
-	return;
-
+      if (optional_tbtab)
+	{
 	  /* Optional fields follow.  Some are variable length.  */
 
-      /* Parameter types, left adjusted bit fields: 0 fixed, 10 single float,
-	 11 double float.  */
-      /* There is an entry for each parameter in a register, in the order that
-	 they occur in the parameter list.  Any intervening arguments on the
-	 stack are ignored.  If the list overflows a long (max possible length
-	 34 bits) then completely leave off all elements that don't fit.  */
+	  /* Parameter types, left adjusted bit fields: 0 fixed, 10 single
+	     float, 11 double float.  */
+	  /* There is an entry for each parameter in a register, in the order
+	     that they occur in the parameter list.  Any intervening arguments
+	     on the stack are ignored.  If the list overflows a long (max
+	     possible length 34 bits) then completely leave off all elements
+	     that don't fit.  */
 	  /* Only emit this long if there was at least one parameter.  */
 	  if (fixed_parms || float_parms)
 	    fprintf (file, "\t.long %d\n", parm_info);
@@ -30460,6 +30460,7 @@ rs6000_output_function_epilogue (FILE *file,
 
 	  fputs ("\t.align 2\n", file);
 	}
+    }
 
   /* Arrange to define .LCTOC1 label, if not already done.  */
   if (need_toc_init)