PPC: Sign-extended result in DoFlooringDivI/DoDivI on 64bit

src/crankshaft/ppc/lithium-codegen-ppc.cc

Index: src/crankshaft/ppc/lithium-codegen-ppc.cc
diff --git a/src/crankshaft/ppc/lithium-codegen-ppc.cc b/src/crankshaft/ppc/lithium-codegen-ppc.cc
index 37a121c1dad201508bac8ce89ece5e3a83d7a568..8ab30ff8bbdd69dc7393d6806b5b1e19623aaeea 100644
--- a/src/crankshaft/ppc/lithium-codegen-ppc.cc
+++ b/src/crankshaft/ppc/lithium-codegen-ppc.cc
@@ -1140,6 +1140,10 @@ void LCodeGen::DoDivI(LDivI* instr) {
     }
   }
 
+#if V8_TARGET_ARCH_PPC64
+  __ extsw(result, result);
+#endif
+
   if (!hdiv->CheckFlag(HInstruction::kAllUsesTruncatingToInt32)) {
     // Deoptimize if remainder is not 0.
     Register scratch = scratch0();
@@ -1333,6 +1337,9 @@ void LCodeGen::DoFlooringDivI(LFlooringDivI* instr) {
   // We performed a truncating division. Correct the result.
   __ subi(result, result, Operand(1));
   __ bind(&done);
+#if V8_TARGET_ARCH_PPC64
+  __ extsw(result, result);
+#endif
 }