[turbofan] Add the TruncateFloat32ToInt32 operator to turbofan.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index c1f816d34bc451a624acf38594fa1b6d1908bbbd..a8e6e35849f350855bf673f48b84381b386b0b24 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -2145,6 +2145,11 @@ Type* Typer::Visitor::TypeChangeFloat64ToUint32(Node* node) {
 }
 
 
+Type* Typer::Visitor::TypeTruncateFloat32ToInt32(Node* node) {
+  return Type::Intersect(Type::Signed32(), Type::UntaggedIntegral32(), zone());
+}
+
+
 Type* Typer::Visitor::TypeTryTruncateFloat32ToInt64(Node* node) {
   return Type::Internal();
 }