[committed] Fix mips calls to move_by_pieces

[Jeff Law]

And the same for the mips port.  I'll go through all kinds of build
tests during the day, including a bootstrap on mipsisa32r2.

Committed.

Jeff

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4be85e3c366..a6e8729f370 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,8 @@
 2018-11-27  Jeff Law  <l...@redhat.com>
 
+       * config/mips/mips.c (mips_block_move_straight): Use RETURN_BEGIN
+       in call to move_by_pieces.
+
        * config/microblaze/microblaze.c (microblaze_block_move_straight): Use
        RETURN_BEGIN in call to move_by_pieces.
        (microblaze_expand_block_move): Likewise.
diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index 17a2a66956e..09b2ae72199 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -8064,7 +8064,7 @@ mips_block_move_straight (rtx dest, rtx src, 
HOST_WIDE_INT length)
       src = adjust_address (src, BLKmode, offset);
       dest = adjust_address (dest, BLKmode, offset);
       move_by_pieces (dest, src, length - offset,
-                     MIN (MEM_ALIGN (src), MEM_ALIGN (dest)), 0);
+                     MIN (MEM_ALIGN (src), MEM_ALIGN (dest)), RETURN_BEGIN);
     }
 }