Revert of [turbofan] Osr value typing + dynamic type checks on entry.

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 a49922bd6bc5a0b075e2e5529e16532918238ab9..447573f18546a2930f5513d3333b5d82761d254b 100644
--- a/src/compiler/simplified-lowering.cc
+++ b/src/compiler/simplified-lowering.cc
@@ -161,8 +161,7 @@
     } else if (NodeProperties::IsEffectEdge(edge)) {
       edge.UpdateTo(effect);
     } else {
-      DCHECK(NodeProperties::IsValueEdge(edge) ||
-             NodeProperties::IsContextEdge(edge));
+      DCHECK(NodeProperties::IsValueEdge(edge));
     }
   }
 }
@@ -1267,30 +1266,6 @@
     return;
   }
 
-  void VisitOsrGuard(Node* node) {
-    VisitInputs(node);
-
-    // Insert a dynamic check for the OSR value type if necessary.
-    switch (OsrGuardTypeOf(node->op())) {
-      case OsrGuardType::kUninitialized:
-        // At this point, we should always have a type for the OsrValue.
-        UNREACHABLE();
-        break;
-      case OsrGuardType::kSignedSmall:
-        if (lower()) {
-          NodeProperties::ChangeOp(node,
-                                   simplified()->CheckedTaggedToTaggedSigned());
-        }
-        return SetOutput(node, MachineRepresentation::kTaggedSigned);
-      case OsrGuardType::kAny:  // Nothing to check.
-        if (lower()) {
-          DeferReplacement(node, node->InputAt(0));
-        }
-        return SetOutput(node, MachineRepresentation::kTagged);
-    }
-    UNREACHABLE();
-  }
-
   // Dispatching routine for visiting the node {node} with the usage {use}.
   // Depending on the operator, propagate new usage info to the inputs.
   void VisitNode(Node* node, Truncation truncation,
@@ -2434,9 +2409,6 @@
         return;
       }
 
-      case IrOpcode::kOsrGuard:
-        return VisitOsrGuard(node);
-
       // Operators with all inputs tagged and no or tagged output have uniform
       // handling.
       case IrOpcode::kEnd:
@@ -2455,9 +2427,9 @@
       case IrOpcode::kThrow:
       case IrOpcode::kBeginRegion:
       case IrOpcode::kFinishRegion:
+      case IrOpcode::kOsrValue:
       case IrOpcode::kProjection:
       case IrOpcode::kObjectState:
-      case IrOpcode::kOsrValue:
 // All JavaScript operators except JSToNumber have uniform handling.
 #define OPCODE_CASE(name) case IrOpcode::k##name:
         JS_SIMPLE_BINOP_LIST(OPCODE_CASE)