[turbofan] Introduce new operators Float32SubPreserveNan and Float64SubPreserveNan for wasm.

src/compiler/x87/instruction-selector-x87.cc

Index: src/compiler/x87/instruction-selector-x87.cc
diff --git a/src/compiler/x87/instruction-selector-x87.cc b/src/compiler/x87/instruction-selector-x87.cc
index 6544fb2d8eb196ab33d6cd833dbad670d58c2031..b487d9448a345b6d073f199ee34eea702d8dded3 100644
--- a/src/compiler/x87/instruction-selector-x87.cc
+++ b/src/compiler/x87/instruction-selector-x87.cc
@@ -897,6 +897,12 @@ void InstructionSelector::VisitFloat32Sub(Node* node) {
   Emit(kX87Float32Sub, g.DefineAsFixed(node, stX_0), 0, nullptr);
 }
 
+void InstructionSelector::VisitFloat32SubPreserveNan(Node* node) {
+  X87OperandGenerator g(this);
+  Emit(kX87PushFloat32, g.NoOutput(), g.Use(node->InputAt(0)));
+  Emit(kX87PushFloat32, g.NoOutput(), g.Use(node->InputAt(1)));
+  Emit(kX87Float32Sub, g.DefineAsFixed(node, stX_0), 0, nullptr);
+}
 
 void InstructionSelector::VisitFloat64Sub(Node* node) {
   X87OperandGenerator g(this);
@@ -905,6 +911,13 @@ void InstructionSelector::VisitFloat64Sub(Node* node) {
   Emit(kX87Float64Sub, g.DefineAsFixed(node, stX_0), 0, nullptr);
 }
 
+void InstructionSelector::VisitFloat64SubPreserveNan(Node* node) {
+  X87OperandGenerator g(this);
+  Emit(kX87PushFloat64, g.NoOutput(), g.Use(node->InputAt(0)));
+  Emit(kX87PushFloat64, g.NoOutput(), g.Use(node->InputAt(1)));
+  Emit(kX87Float64Sub, g.DefineAsFixed(node, stX_0), 0, nullptr);
+}
+
 
 void InstructionSelector::VisitFloat32Mul(Node* node) {
   X87OperandGenerator g(this);