Optimize execution speed (#374)

* Set ALWAYS_INLINE flag for SmallValue <-> Value convertor function
* Implement ScriptGeneratorFunctionObject for remove if-statement in FunctionCall
* Remove calling Object::call in CallFunction, CallFunctionWithReceiver opcode
* if function uses global variable only, we should not use heap env for the function
* Don't use bitfield for ExecutionState::m_inStrictMode because we have only one flag at there.
* Remove useless submodules (test262-master, test262-harness)

Signed-off-by: seonghyun kim <sh8281.kim@samsung.com>

src/runtime/ScriptGeneratorFunctionObject.cpp

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2019-present Samsung Electronics Co., Ltd
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
+ *  USA
+ */
+
+#include "Escargot.h"
+#include "ScriptGeneratorFunctionObject.h"
+
+#include "FunctionObjectInlines.h"
+
+namespace Escargot {
+
+class ScriptGeneratorFunctionObjectThisValueBinder {
+public:
+    Value operator()(ExecutionState& calleeState, ScriptGeneratorFunctionObject* self, const Value& thisArgument, bool isStrict)
+    {
+        Value thisValue = self->thisValue();
+        if (thisValue.isEmpty()) {
+            // OrdinaryCallBindThis ( F, calleeContext, thisArgument )
+            // Let thisMode be the value of F’s [[ThisMode]] internal slot.
+            // If thisMode is lexical, return NormalCompletion(undefined).
+            // --> thisMode is always not lexcial because this is class ctor.
+            // Let calleeRealm be the value of F’s [[Realm]] internal slot.
+            // Let localEnv be the LexicalEnvironment of calleeContext.
+            ASSERT(calleeState.context() == self->codeBlock()->context());
+
+            if (isStrict) {
+                // If thisMode is strict, let thisValue be thisArgument.
+                return thisArgument;
+            } else {
+                // Else
+                // if thisArgument is null or undefined, then
+                // Let thisValue be calleeRealm.[[globalThis]]
+                if (thisArgument.isUndefinedOrNull()) {
+                    return calleeState.context()->globalObject();
+                } else {
+                    // Else
+                    // Let thisValue be ToObject(thisArgument).
+                    // Assert: thisValue is not an abrupt completion.
+                    // NOTE ToObject produces wrapper objects using calleeRealm.
+                    return thisArgument.toObject(calleeState);
+                }
+            }
+        } else {
+            ASSERT(self->codeBlock()->isArrowFunctionExpression());
+            return thisValue;
+        }
+    }
+};
+
+Value ScriptGeneratorFunctionObject::call(ExecutionState& state, const Value& thisValue, const size_t argc, NULLABLE Value* argv)
+{
+    return FunctionObjectProcessCallGenerator::processCall<ScriptGeneratorFunctionObject, true, false, false, false, ScriptGeneratorFunctionObjectThisValueBinder, FunctionObjectNewTargetBinder, FunctionObjectReturnValueBinder>(state, this, thisValue, argc, argv, nullptr);
+}
+
+Object* ScriptGeneratorFunctionObject::construct(ExecutionState& state, const size_t argc, NULLABLE Value* argv, Object* newTarget)
+{
+    ErrorObject::throwBuiltinError(state, ErrorObject::TypeError, "Generator cannot be invoked with 'new'");
+    ASSERT_NOT_REACHED();
+    return nullptr;
+}
+}