[turbofan] Add the TruncateFloat32ToInt32 operator to turbofan.

src/compiler/x87/code-generator-x87.cc

Index: src/compiler/x87/code-generator-x87.cc
diff --git a/src/compiler/x87/code-generator-x87.cc b/src/compiler/x87/code-generator-x87.cc
index f4e334dbb2624ab5f417a86349e065b3836d4f91..96e029111bf618ae87a8b15eed96194c4fb3ef09 100644
--- a/src/compiler/x87/code-generator-x87.cc
+++ b/src/compiler/x87/code-generator-x87.cc
@@ -1005,6 +1005,16 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       __ LoadUint32NoSSE2(i.InputRegister(0));
       break;
     }
+    case kX87Float32ToInt32: {
+      if (!instr->InputAt(0)->IsDoubleRegister()) {
+        __ fld_s(i.InputOperand(0));
+      }
+      __ TruncateX87TOSToI(i.OutputRegister(0));
+      if (!instr->InputAt(0)->IsDoubleRegister()) {
+        __ fstp(0);
+      }
+      break;
+    }
     case kX87Float64ToInt32: {
       if (!instr->InputAt(0)->IsDoubleRegister()) {
         __ fld_d(i.InputOperand(0));