tcg/ppc: Fix TCG_TARGET_CALL_{ARG,RET}_I128 for ppc32

For both _CALL_SYSV and _CALL_DARWIN, return is by reference,
not in 4 integer registers.  For _CALL_SYSV, argument is also
by reference.

This error resulted in

    $ ./qemu-system-i386 -nographic
    qemu-system-i386: tcg/ppc/tcg-target.c.inc:185: \
        tcg_target_call_oarg_reg: Assertion `slot >= 0 && slot <= 1' failed.

Fixes: 5427a9a7604 ("tcg: Add TCG_TARGET_CALL_{RET,ARG}_I128")
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/ppc/tcg-target.c.inc

@@ -46,17 +46,18 @@
 
 #if TCG_TARGET_REG_BITS == 64
 # define TCG_TARGET_CALL_ARG_I32   TCG_CALL_ARG_EXTEND
+# define TCG_TARGET_CALL_RET_I128  TCG_CALL_RET_NORMAL
 #else
 # define TCG_TARGET_CALL_ARG_I32   TCG_CALL_ARG_NORMAL
+# define TCG_TARGET_CALL_RET_I128  TCG_CALL_RET_BY_REF
 #endif
 #ifdef _CALL_SYSV
 # define TCG_TARGET_CALL_ARG_I64   TCG_CALL_ARG_EVEN
+# define TCG_TARGET_CALL_ARG_I128  TCG_CALL_ARG_BY_REF
 #else
 # define TCG_TARGET_CALL_ARG_I64   TCG_CALL_ARG_NORMAL
+# define TCG_TARGET_CALL_ARG_I128  TCG_CALL_ARG_NORMAL
 #endif
-/* Note sysv arg alignment applies only to 2-word types, not more. */
-#define TCG_TARGET_CALL_ARG_I128   TCG_CALL_ARG_NORMAL
-#define TCG_TARGET_CALL_RET_I128   TCG_CALL_RET_NORMAL
 
 /* For some memory operations, we need a scratch that isn't R0.  For the AIX
    calling convention, we can re-use the TOC register since we'll be reloading