[turbofan] remove register operand cache

src/compiler/instruction.h

Index: src/compiler/instruction.h
diff --git a/src/compiler/instruction.h b/src/compiler/instruction.h
index fc7b033a6dd787d1cabf99ffaba13c1d8bb431c7..cf1883f8a61711ae0ac58057cf1489fcd2cef49a 100644
--- a/src/compiler/instruction.h
+++ b/src/compiler/instruction.h
@@ -62,6 +62,10 @@ class InstructionOperand {
     return value_ < op.value_;
   }
 
+  bool operator==(const InstructionOperand& op) const {
+    return value_ == op.value_;
+  }
+
   template <typename SubKindOperand>
   static SubKindOperand* New(Zone* zone, const SubKindOperand& op) {
     void* buffer = zone->New(sizeof(op));