[turbofan] Add the RoundInt32ToFloat32 operator to turbofan.

src/compiler/ppc/code-generator-ppc.cc

Index: src/compiler/ppc/code-generator-ppc.cc
diff --git a/src/compiler/ppc/code-generator-ppc.cc b/src/compiler/ppc/code-generator-ppc.cc
index 6fe674e4f2cdffcb75efe2fdfe740b5e67f55470..e20b5ec6e75be1d5b8a29d1555c2f2085567735b 100644
--- a/src/compiler/ppc/code-generator-ppc.cc
+++ b/src/compiler/ppc/code-generator-ppc.cc
@@ -1194,6 +1194,11 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       DCHECK_EQ(LeaveRC, i.OutputRCBit());
       break;
 #endif
+    case kPPC_Int32ToFloat32:
+      __ ConvertIntToFloat(i.OutputDoubleRegister(), i.InputRegister(0),
+                           kScratchReg);
+      DCHECK_EQ(LeaveRC, i.OutputRCBit());
+      break;
     case kPPC_Int32ToDouble:
       __ ConvertIntToDouble(i.InputRegister(0), i.OutputDoubleRegister());
       DCHECK_EQ(LeaveRC, i.OutputRCBit());