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

src/compiler/wasm-compiler.cc

Index: src/compiler/wasm-compiler.cc
diff --git a/src/compiler/wasm-compiler.cc b/src/compiler/wasm-compiler.cc
index 8357635e017879f12aaa9baaf0a16a0d035c331a..471f1b53df24a797938e67876a29360ec61cde52 100644
--- a/src/compiler/wasm-compiler.cc
+++ b/src/compiler/wasm-compiler.cc
@@ -535,7 +535,7 @@ Node* WasmGraphBuilder::Binop(wasm::WasmOpcode opcode, Node* left, Node* right,
       op = m->Float32Add();
       break;
     case wasm::kExprF32Sub:
-      op = m->Float32Sub();
+      op = m->Float32SubPreserveNan();
       break;
     case wasm::kExprF32Mul:
       op = m->Float32Mul();
@@ -566,7 +566,7 @@ Node* WasmGraphBuilder::Binop(wasm::WasmOpcode opcode, Node* left, Node* right,
       op = m->Float64Add();
       break;
     case wasm::kExprF64Sub:
-      op = m->Float64Sub();
+      op = m->Float64SubPreserveNan();
       break;
     case wasm::kExprF64Mul:
       op = m->Float64Mul();