[turbofan] Add the TruncateFloat32ToInt32 operator to turbofan.

src/compiler/ia32/code-generator-ia32.cc

Index: src/compiler/ia32/code-generator-ia32.cc
diff --git a/src/compiler/ia32/code-generator-ia32.cc b/src/compiler/ia32/code-generator-ia32.cc
index f63bc22e4344fe65a875ea3c7cc341a98caa362a..aa95293333ad5bf1eddf9c65ca712f9555834c54 100644
--- a/src/compiler/ia32/code-generator-ia32.cc
+++ b/src/compiler/ia32/code-generator-ia32.cc
@@ -739,6 +739,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kSSEFloat64ToFloat32:
       __ cvtsd2ss(i.OutputDoubleRegister(), i.InputOperand(0));
       break;
+    case kSSEFloat32ToInt32:
+      __ cvttss2si(i.OutputRegister(), i.InputOperand(0));
+      break;
     case kSSEFloat64ToInt32:
       __ cvttsd2si(i.OutputRegister(), i.InputOperand(0));
       break;