[wasm]implement simd lowering for f32x4->i32x4, i32x4 min/max and shift instructions

src/compiler/simd-scalar-lowering.h

Index: src/compiler/simd-scalar-lowering.h
diff --git a/src/compiler/simd-scalar-lowering.h b/src/compiler/simd-scalar-lowering.h
index 04f9d0ff77ca2dc6f2c4438a31e8ff807a99210b..76eeb9b8e24c851f3976a319dbbae78e7b2c68a8 100644
--- a/src/compiler/simd-scalar-lowering.h
+++ b/src/compiler/simd-scalar-lowering.h
@@ -7,6 +7,7 @@
 
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
+#include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node-marker.h"
 #include "src/zone/zone-containers.h"
@@ -17,8 +18,7 @@ namespace compiler {
 
 class SimdScalarLowering {
  public:
-  SimdScalarLowering(Graph* graph, MachineOperatorBuilder* machine,
-                     CommonOperatorBuilder* common, Zone* zone,
+  SimdScalarLowering(JSGraph* jsgraph,
                      Signature<MachineRepresentation>* signature);
 
   void LowerGraph();
@@ -38,10 +38,15 @@ class SimdScalarLowering {
     SimdType type;  // represents what input type is expected
   };
 
-  Zone* zone() const { return zone_; }
-  Graph* graph() const { return graph_; }
-  MachineOperatorBuilder* machine() const { return machine_; }
-  CommonOperatorBuilder* common() const { return common_; }
+  struct NodeState {
+    Node* node;
+    int input_index;
+  };
+
+  Zone* zone() const { return jsgraph_->zone(); }
+  Graph* graph() const { return jsgraph_->graph(); }
+  MachineOperatorBuilder* machine() const { return jsgraph_->machine(); }
+  CommonOperatorBuilder* common() const { return jsgraph_->common(); }
   Signature<MachineRepresentation>* signature() const { return signature_; }
 
   void LowerNode(Node* node);
@@ -61,16 +66,12 @@ class SimdScalarLowering {
                     const Operator* store_op, SimdType rep_type);
   void LowerBinaryOp(Node* node, SimdType input_rep_type, const Operator* op);
   void LowerUnaryOp(Node* node, SimdType input_rep_type, const Operator* op);
+  void LowerIntMinMax(Node* node, const Operator* op, bool is_max);
+  void LowerConvertFromFloat(Node* node, bool is_signed);
+  void LowerShiftOp(Node* node, const Operator* op);
+  Node* BuildF64Trunc(Node* input);
 
-  struct NodeState {
-    Node* node;
-    int input_index;
-  };
-
-  Zone* zone_;
-  Graph* const graph_;
-  MachineOperatorBuilder* machine_;
-  CommonOperatorBuilder* common_;
+  JSGraph* const jsgraph_;
   NodeMarker<State> state_;
   ZoneDeque<NodeState> stack_;
   Replacement* replacements_;