Make the kernel dwarf stack unwinder work for ARC targets.

	* config//tc-arc.c (tc_arc_frame_initial_instructions): Use
	cfi_add_CFA_def_cfa to generate default CFA with offset
	* testsuite/gas/cfi/cfi-arc-1.d: Update expected output.

gas/ChangeLog

+2016-06-27  Vineet Gupta  <vgupta@synopsys.com>
+
+	* config//tc-arc.c (tc_arc_frame_initial_instructions): Use
+	cfi_add_CFA_def_cfa to generate default CFA with offset
+	* testsuite/gas/cfi/cfi-arc-1.d: Update expected output.
+
 2016-06-27  Nick Clifton  <nickc@redhat.com>
 
 	PR gas/20247

gas/config/tc-arc.c

@@ -4160,7 +4160,7 @@ void
 tc_arc_frame_initial_instructions (void)
 {
   /* Stack pointer is register 28.  */
-  cfi_add_CFA_def_cfa_register (28);
+  cfi_add_CFA_def_cfa (28, 0);
 }
 
 int

gas/testsuite/gas/cfi/cfi-arc-1.d

@@ -11,8 +11,7 @@ Contents of the .eh_frame section:
   Return address column: 31
   Augmentation data:     1b
 
-  DW_CFA_def_cfa_register: r28
-  DW_CFA_nop
+  DW_CFA_def_cfa: r28 ofs 0
 
 00000014 00000020 00000018 FDE cie=00000000 pc=00000000..00000010
   DW_CFA_advance_loc: 4 to 00000004