Revert of [turbofan] Introduce LoadFunctionPrototype simplified operator.

src/compiler/simplified-lowering.cc

Index: src/compiler/simplified-lowering.cc
diff --git a/src/compiler/simplified-lowering.cc b/src/compiler/simplified-lowering.cc
index 519a9e63741fa2ac335d71449f597c9c962eb336..9e1cc7b5a29516fcef4280564048fc68f5aea16e 100644
--- a/src/compiler/simplified-lowering.cc
+++ b/src/compiler/simplified-lowering.cc
@@ -2383,12 +2383,6 @@
                      TruncatingUseInfoFromRepresentation(rep));  // value
         ProcessRemainingInputs(node, 5);
         SetOutput(node, MachineRepresentation::kNone);
-        return;
-      }
-      case IrOpcode::kLoadFunctionPrototype: {
-        if (truncation.IsUnused()) return VisitUnused(node);
-        VisitUnop(node, UseInfo::AnyTagged(),
-                  MachineRepresentation::kTaggedPointer);
         return;
       }
       case IrOpcode::kPlainPrimitiveToNumber: {