[turbofan] Make Float32Neg and Float64Neg mandatory operators.

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

Index: src/compiler/mips/instruction-selector-mips.cc
diff --git a/src/compiler/mips/instruction-selector-mips.cc b/src/compiler/mips/instruction-selector-mips.cc
index e4afad20f48753c16fba7e2a0f75aa75515fca70..d4b68e4ab25e25bb14d04bc3e1419dc022905871 100644
--- a/src/compiler/mips/instruction-selector-mips.cc
+++ b/src/compiler/mips/instruction-selector-mips.cc
@@ -894,9 +894,13 @@ void InstructionSelector::VisitFloat64RoundTiesEven(Node* node) {
   VisitRR(this, kMipsFloat64RoundTiesEven, node);
 }
 
-void InstructionSelector::VisitFloat32Neg(Node* node) { UNREACHABLE(); }
+void InstructionSelector::VisitFloat32Neg(Node* node) {
+  VisitRR(this, kMipsNegS, node);
+}
 
-void InstructionSelector::VisitFloat64Neg(Node* node) { UNREACHABLE(); }
+void InstructionSelector::VisitFloat64Neg(Node* node) {
+  VisitRR(this, kMipsNegD, node);
+}
 
 void InstructionSelector::VisitFloat64Ieee754Binop(Node* node,
                                                    InstructionCode opcode) {