[turbofan] Turn common Guard operator into simplified TypeGuard.

src/compiler/common-operator.cc

Index: src/compiler/common-operator.cc
diff --git a/src/compiler/common-operator.cc b/src/compiler/common-operator.cc
index 7940c68204125277e8fdb987f05f7914b8d3c4d6..d3f697256c6dfeb56f34667e136a3b55c30f61c1 100644
--- a/src/compiler/common-operator.cc
+++ b/src/compiler/common-operator.cc
@@ -760,15 +760,6 @@ const Operator* CommonOperatorBuilder::EffectPhi(int effect_input_count) {
 }
 
 
-const Operator* CommonOperatorBuilder::Guard(Type* type) {
-  return new (zone()) Operator1<Type*>(      // --
-      IrOpcode::kGuard, Operator::kKontrol,  // opcode
-      "Guard",                               // name
-      1, 0, 1, 1, 0, 0,                      // counts
-      type);                                 // parameter
-}
-
-
 const Operator* CommonOperatorBuilder::StateValues(int arguments) {
   switch (arguments) {
 #define CACHED_STATE_VALUES(arguments) \