[PATCH, 4.6, committed] Fix typo in rs6000.md call pattern for AIX

[David Edelsohn]

A backport of another patch introduced a cut-and-paste typo in one of
the AIX call patterns, generating a DImode memory operand in 32 bit
mode.  Fixed with the following patch.

- David

        * config/rs6000/rs6000.md (call_value_indirect_aix32): Fix typo
        in mode of operand[4].

Index: rs6000.md
===================================================================
--- rs6000.md   (revision 183273)
+++ rs6000.md   (working copy)
@@ -12241,8 +12241,8 @@
   "
 {
   operands[3] = gen_reg_rtx (SImode);
-  operands[4] = gen_rtx_MEM (DImode,
-                            gen_rtx_PLUS (DImode, stack_pointer_rtx,
+  operands[4] = gen_rtx_MEM (SImode,
+                            gen_rtx_PLUS (SImode, stack_pointer_rtx,
                                           GEN_INT (20)));