Refactor snapshots pieces to include a section for loading instructions into the heap of a regular …

runtime/vm/gc_sweeper.cc

Index: runtime/vm/gc_sweeper.cc
diff --git a/runtime/vm/gc_sweeper.cc b/runtime/vm/gc_sweeper.cc
index f779b49646d417306074d3a0e671537731b4ac14..609afb9aa9e9a0f4dcfef893afdbda553b8fe297 100644
--- a/runtime/vm/gc_sweeper.cc
+++ b/runtime/vm/gc_sweeper.cc
@@ -16,6 +16,11 @@
 namespace dart {
 
 bool GCSweeper::SweepPage(HeapPage* page, FreeList* freelist, bool locked) {
+  if (page->embedder_allocated()) {
+    // Don't clear mark bits.
+    return true;
+  }
+
   // Keep track whether this page is still in use.
   bool in_use = false;