[turbofan] Remove the FloatXXSubPreserveNan operators.

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

Index: src/compiler/mips/code-generator-mips.cc
diff --git a/src/compiler/mips/code-generator-mips.cc b/src/compiler/mips/code-generator-mips.cc
index 011a74313712b7fc91e3a29f582441c256be22da..073c9f560c572738e596d8756a20010ae082f015 100644
--- a/src/compiler/mips/code-generator-mips.cc
+++ b/src/compiler/mips/code-generator-mips.cc
@@ -1055,11 +1055,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ sub_s(i.OutputDoubleRegister(), i.InputDoubleRegister(0),
                i.InputDoubleRegister(1));
       break;
-    case kMipsSubPreserveNanS:
-      __ SubNanPreservePayloadAndSign_s(i.OutputDoubleRegister(),
-                                        i.InputDoubleRegister(0),
-                                        i.InputDoubleRegister(1));
-      break;
     case kMipsMulS:
       // TODO(plind): add special case: right op is -1.0, see arm port.
       __ mul_s(i.OutputDoubleRegister(), i.InputDoubleRegister(0),
@@ -1126,11 +1121,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ sub_d(i.OutputDoubleRegister(), i.InputDoubleRegister(0),
                i.InputDoubleRegister(1));
       break;
-    case kMipsSubPreserveNanD:
-      __ SubNanPreservePayloadAndSign_d(i.OutputDoubleRegister(),
-                                        i.InputDoubleRegister(0),
-                                        i.InputDoubleRegister(1));
-      break;
     case kMipsMulD:
       // TODO(plind): add special case: right op is -1.0, see arm port.
       __ mul_d(i.OutputDoubleRegister(), i.InputDoubleRegister(0),