[Interpreter] Adds support for const/let variables to interpreter.

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

Index: test/cctest/compiler/test-run-bytecode-graph-builder.cc
diff --git a/test/cctest/compiler/test-run-bytecode-graph-builder.cc b/test/cctest/compiler/test-run-bytecode-graph-builder.cc
index c24bcc907272f8a7ab2f6a414a91dede705ab1d7..dfc98ffc7110304c4f76339d257c433fd77f9900 100644
--- a/test/cctest/compiler/test-run-bytecode-graph-builder.cc
+++ b/test/cctest/compiler/test-run-bytecode-graph-builder.cc
@@ -2603,7 +2603,6 @@ TEST(JumpWithConstantsAndWideConstants) {
 TEST(BytecodeGraphBuilderDoExpressions) {
   bool old_flag = FLAG_harmony_do_expressions;
   FLAG_harmony_do_expressions = true;
-
   HandleAndZoneScope scope;
   Isolate* isolate = scope.main_isolate();
   Zone* zone = scope.main_zone();
@@ -2633,6 +2632,30 @@ TEST(BytecodeGraphBuilderDoExpressions) {
   FLAG_harmony_do_expressions = old_flag;
 }
 
+TEST(JumpOnHole) {

[rmcilroy, 2016/02/03 12:28:26]

Could you replicate the test-interpreter tests here rather than testing for just
JumpOnHole, I think that would be more useful.

[mythria, 2016/02/04 10:28:53]

Done. Now I have a 1500 line cl :)

+  HandleAndZoneScope scope;
+  Isolate* isolate = scope.main_isolate();
+  Zone* zone = scope.main_zone();
+  Factory* factory = isolate->factory();
+  // TODO(mythria): Add tests to check JumpIfHole. Initializing 'this' via super
+  // calls uses JumpIfHole.
+  ExpectedSnippet<0> snippets[] = {
+      {"let x = 1; x = 2; return x;", {factory->NewNumberFromInt(2)}},
+      {"const x = 3; return x;", {factory->NewNumberFromInt(3)}},
+  };
+
+  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