[turbofan] Fix OSR entry in case label.

src/compiler/ast-graph-builder.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/ast-graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/linkage.h"
@@ skipping 1186 matching lines @@
 
 void AstGraphBuilder::VisitSwitchStatement(SwitchStatement* stmt) {
   ZoneList<CaseClause*>* clauses = stmt->cases();
   SwitchBuilder compare_switch(this, clauses->length());
   ControlScopeForBreakable scope(this, stmt, &compare_switch);
   compare_switch.BeginSwitch();
   int default_index = -1;
 
   // Keep the switch value on the stack until a case matches.
   VisitForValue(stmt->tag());
-  Node* tag = environment()->Top();
 
   // Iterate over all cases and create nodes for label comparison.
   for (int i = 0; i < clauses->length(); i++) {
     CaseClause* clause = clauses->at(i);
 
     // The default is not a test, remember index.
     if (clause->is_default()) {
       default_index = i;
       continue;
     }
 
     // Create nodes to perform label comparison as if via '==='. The switch
     // value is still on the operand stack while the label is evaluated.
     VisitForValue(clause->label());
     Node* label = environment()->Pop();
+    Node* tag = environment()->Top();
     const Operator* op = javascript()->StrictEqual();
     Node* condition = NewNode(op, tag, label);
     compare_switch.BeginLabel(i, condition);
 
     // Discard the switch value at label match.
     environment()->Pop();
     compare_switch.EndLabel();
   }
 
   // Discard the switch value and mark the default case.
@@ skipping 3063 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8