PPC: Fix simulator.

R=joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1590423002

Cr-Commit-Position: refs/heads/master@{#33343}

src/ppc/assembler-ppc.h

@@ -53,7 +53,7 @@
 #define ABI_PASSES_HANDLES_IN_REGS \
   (!V8_HOST_ARCH_PPC || V8_OS_AIX || V8_TARGET_ARCH_PPC64)
 
-#if (!V8_HOST_ARCH_PPC || !V8_TARGET_ARCH_PPC64 || V8_TARGET_LITTLE_ENDIAN)
+#if !V8_HOST_ARCH_PPC || !V8_TARGET_ARCH_PPC64 || V8_TARGET_LITTLE_ENDIAN
 #define ABI_RETURNS_OBJECT_PAIRS_IN_REGS 1
 #else
 #define ABI_RETURNS_OBJECT_PAIRS_IN_REGS 0

src/ppc/simulator-ppc.cc

@@ -1235,9 +1235,9 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
       const int kArgCount = 6;
       int arg0_regnum = 3;
       intptr_t result_buffer = 0;
-      if (redirection->type() == ExternalReference::BUILTIN_CALL_TRIPLE ||
-          (redirection->type() == ExternalReference::BUILTIN_CALL_PAIR &&
-           !ABI_RETURNS_OBJECT_PAIRS_IN_REGS)) {
+      bool uses_result_buffer =
+          redirection->type() == ExternalReference::BUILTIN_CALL_TRIPLE;
+      if (uses_result_buffer) {
         result_buffer = get_register(r3);
         arg0_regnum++;
       }