[heap] Reland prepare code for smaller large object allocation limit than max allocatable memory.

test/cctest/test-weaksets.cc

Index: test/cctest/test-weaksets.cc
diff --git a/test/cctest/test-weaksets.cc b/test/cctest/test-weaksets.cc
index b6f0a784204b1b9adaab45ca97677a8105befa96..411c92168d5716591b1c69545b5b09649f040ea2 100644
--- a/test/cctest/test-weaksets.cc
+++ b/test/cctest/test-weaksets.cc
@@ -187,8 +187,7 @@ TEST(WeakSet_Regress2060a) {
 
   // Start second old-space page so that values land on evacuation candidate.
   Page* first_page = heap->old_space()->anchor()->next_page();
-  int dummy_array_size = Page::kMaxRegularHeapObjectSize - 92 * KB;
-  factory->NewFixedArray(dummy_array_size / kPointerSize, TENURED);
+  SimulateFullSpace(heap->old_space());
 
   // Fill up weak set with values on an evacuation candidate.
   {
@@ -227,8 +226,7 @@ TEST(WeakSet_Regress2060b) {
 
   // Start second old-space page so that keys land on evacuation candidate.
   Page* first_page = heap->old_space()->anchor()->next_page();
-  int dummy_array_size = Page::kMaxRegularHeapObjectSize - 92 * KB;
-  factory->NewFixedArray(dummy_array_size / kPointerSize, TENURED);
+  SimulateFullSpace(heap->old_space());
 
   // Fill up weak set with keys on an evacuation candidate.
   Handle<JSObject> keys[32];