Do not try to inline if the function has an illegal redeclaration.

src/hydrogen.cc

 // Copyright 2013 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/hydrogen.h"
 
 #include <sstream>
 
 #include "src/v8.h"
 
@@ skipping 7913 matching lines @@
   if (!Compiler::ParseAndAnalyze(&target_info)) {
     if (target_info.isolate()->has_pending_exception()) {
       // Parse or scope error, never optimize this function.
       SetStackOverflow();
       target_shared->DisableOptimization(kParseScopeError);
     }
     TraceInline(target, caller, "parse failure");
     return false;
   }
 
+  if (target_info.scope()->HasIllegalRedeclaration()) {
+    TraceInline(target, caller, "target has illegal redeclaration");
+    return false;
+  }
+
   if (target_info.scope()->num_heap_slots() > 0) {
     TraceInline(target, caller, "target has context-allocated variables");
     return false;
   }
   FunctionLiteral* function = target_info.function();
 
   // The following conditions must be checked again after re-parsing, because
   // earlier the information might not have been complete due to lazy parsing.
   nodes_added = function->ast_node_count();
   if (nodes_added > Min(FLAG_max_inlined_nodes, kUnlimitedMaxInlinedNodes)) {
@@ skipping 4836 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal