ParserBase should accept ESCAPED_STRICT_RESERVED_WORD as an identifier

test/cctest/test-parsing.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 9431 matching lines @@
       DCHECK_NULL(scope->sibling());
       DCHECK(scope->is_function_scope());
       const i::AstRawString* var_name =
           info.ast_value_factory()->GetOneByteString("my_var");
       i::Variable* var = scope->Lookup(var_name);
       CHECK_EQ(inners[i].ctxt_allocate,
                i::ScopeTestHelper::MustAllocateInContext(var));
     }
   }
 }
+
+TEST(EscapedStrictReservedWord) {
+  // Test that identifiers which are both escaped and only reserved in the
+  // strict mode are accepted in non-strict mode.
+  const char* context_data[][2] = {{"", ""}, {NULL, NULL}};
+
+  const char* statement_data[] = {"if (true) l\u0065t: ;",
+                                  "function l\u0065t() { }",
+                                  "(function l\u0065t() { })",
+                                  "async function l\u0065t() { }",
+                                  "(async function l\u0065t() { })",
+                                  "l\u0065t => 42",
+                                  "async l\u0065t => 42",
+                                  NULL};
+
+  RunParserSyncTest(context_data, statement_data, kSuccess);
+}