[heap] Parallel newspace evacuation, semispace copy, and compaction \o/

test/cctest/heap/test-heap.cc

Index: test/cctest/heap/test-heap.cc
diff --git a/test/cctest/heap/test-heap.cc b/test/cctest/heap/test-heap.cc
index 726887a23a6ee785167817c42343f789eb4b5973..d156dc0a0ca1b7d8a049bedd997def4bccf9c5ab 100644
--- a/test/cctest/heap/test-heap.cc
+++ b/test/cctest/heap/test-heap.cc
@@ -3514,6 +3514,10 @@ TEST(ReleaseOverReservedPages) {
   // The optimizer can allocate stuff, messing up the test.
   i::FLAG_crankshaft = false;
   i::FLAG_always_opt = false;
+  // Parallel compaction increases fragmentation, depending on how existing
+  // memory is distributed. Since this is non-deterministic because of
+  // concurrent sweeping, we disable it for this test.
+  i::FLAG_parallel_compaction = false;
   CcTest::InitializeVM();
   Isolate* isolate = CcTest::i_isolate();
   Factory* factory = isolate->factory();