target-ppc: fix default qNaN

On PPC the default qNaN doesn't have the sign bit set.

Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

target-ppc/op_helper.c

diff --git a/target-ppc/op_helper.c b/target-ppc/op_helper.c
index 31520ab..c69ffc9 100644
--- a/target-ppc/op_helper.c
+++ b/target-ppc/op_helper.c
@@ -643,7 +643,7 @@
         env->fpscr &= ~((1 << FPSCR_FR) | (1 << FPSCR_FI));
         if (ve == 0) {
             /* Set the result to quiet NaN */
-            ret = 0xFFF8000000000000ULL;
+            ret = 0x7FF8000000000000ULL;
             env->fpscr &= ~(0xF << FPSCR_FPCC);
             env->fpscr |= 0x11 << FPSCR_FPCC;
         }
@@ -654,7 +654,7 @@
         env->fpscr &= ~((1 << FPSCR_FR) | (1 << FPSCR_FI));
         if (ve == 0) {
             /* Set the result to quiet NaN */
-            ret = 0xFFF8000000000000ULL;
+            ret = 0x7FF8000000000000ULL;
             env->fpscr &= ~(0xF << FPSCR_FPCC);
             env->fpscr |= 0x11 << FPSCR_FPCC;
         }