Reland "Implement Math.random() purely in JavaScript" plus fixes.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 7064ea9e638ff568daf45b35889c7094d53d019f..6e2ad06ea7fec2e829eb312740849ad207fbf6a6 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -5459,6 +5459,16 @@ void JSArrayBuffer::set_is_external(bool value) {
 }
 
 
+bool JSArrayBuffer::should_be_freed() {
+  return BooleanBit::get(flag(), kShouldBeFreed);
+}
+
+
+void JSArrayBuffer::set_should_be_freed(bool value) {
+  set_flag(BooleanBit::set(flag(), kShouldBeFreed, value));
+}
+
+
 ACCESSORS(JSArrayBuffer, weak_next, Object, kWeakNextOffset)
 ACCESSORS(JSArrayBuffer, weak_first_view, Object, kWeakFirstViewOffset)