[Interpreter] Implement ForIn in bytecode graph builder.

test/cctest/compiler/test-run-bytecode-graph-builder.cc

 // Copyright 2015 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 <utility>
 
 #include "src/compiler/pipeline.h"
 #include "src/execution.h"
 #include "src/handles.h"
 #include "src/interpreter/bytecode-array-builder.h"
@@ skipping 1820 matching lines @@
     SNPrintF(script, "function %s() { %s }\n%s();", kFunctionName,
              snippets[i].code_snippet, kFunctionName);
 
     BytecodeGraphTester tester(isolate, zone, script.start());
     auto callable = tester.GetCallable<>();
     Handle<Object> return_value = callable().ToHandleChecked();
     CHECK(return_value->SameValue(*snippets[i].return_value()));
   }
 }
 
+
+TEST(BytecodeGraphBuilderForIn) {
+  HandleAndZoneScope scope;
+  Isolate* isolate = scope.main_isolate();
+  Zone* zone = scope.main_zone();
+  Factory* factory = isolate->factory();
+  ExpectedSnippet<0> snippets[] = {
+      {"var last = 0;\n"
+       "for (var x in [ 10, 20, 30 ]) {\n"
+       "  last = x;\n"
+       "}\n"
+       "return +last;",
+       {factory->NewNumberFromInt(2)}},
+      {"var first = -1;\n"
+       "for (var x in [ 10, 20, 30 ]) {\n"
+       "  first = +x;\n"
+       "  if (first > 0) break;\n"
+       "}\n"
+       "return first;",
+       {factory->NewNumberFromInt(1)}},
+      {"var first = -1;\n"
+       "for (var x in [ 10, 20, 30 ]) {\n"
+       "  if (first >= 0) continue;\n"
+       "  first = x;\n"
+       "}\n"
+       "return +first;",
+       {factory->NewNumberFromInt(0)}},
+      {"var sum = 0;\n"
+       "for (var x in [ 10, 20, 30 ]) {\n"
+       "  for (var y in [ 11, 22, 33, 44, 55, 66, 77 ]) {\n"
+       "    sum += 1;\n"
+       "  }\n"
+       "}\n"
+       "return sum;",
+       {factory->NewNumberFromInt(21)}},
+      // TODO(oth): test break/continue nested.
+  };
+
+  for (size_t i = 0; i < arraysize(snippets); i++) {
+    ScopedVector<char> script(1024);
+    SNPrintF(script, "function %s() { %s }\n%s();", kFunctionName,
+             snippets[i].code_snippet, kFunctionName);
+
+    BytecodeGraphTester tester(isolate, zone, script.start());
+    auto callable = tester.GetCallable<>();
+    Handle<Object> return_value = callable().ToHandleChecked();
+    CHECK(return_value->SameValue(*snippets[i].return_value()));
+  }
+}
+
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8