R_MIPS_JALR failures

This is a fix for my PR70890 patch, which incorrectly removed all
REG_EQUIV notes rather than just one regarding a reg that dies.

	PR rtl-optimization/78325
	PR rtl-optimization/70890
	* ira.c (combine_and_move_insns): Only remove REG_EQUIV notes
	for dead regno.

From-SVN: r242525

gcc/ChangeLog

+2016-11-17  Alan Modra  <amodra@gmail.com>
+
+	PR rtl-optimization/78325
+	PR rtl-optimization/70890
+	* ira.c (combine_and_move_insns): Only remove REG_EQUIV notes
+	for dead regno.
+
 2016-11-16  Jason Merrill  <jason@redhat.com>
 
 	* rtl.h: Declare gt_ggc_mx and gt_pch_nx.

gcc/ira.c

@@ -3747,7 +3747,7 @@ combine_and_move_insns (void)
 	     use_insn, when regno was seen as non-local.  Now that
 	     regno is local to this block, and dies, such an
 	     equivalence is invalid.  */
-	  if (find_reg_note (use_insn, REG_EQUIV, NULL_RTX))
+	  if (find_reg_note (use_insn, REG_EQUIV, regno_reg_rtx[regno]))
 	    {
 	      rtx set = single_set (use_insn);
 	      if (set && REG_P (SET_DEST (set)))