Remove dead code in RuntimeMemory
Add Executive.GetGCRoots()
RuntimeMemory.GC()
Implement basic mark and sweep
Code clean up
Code cleanup
Add HeapMarkSweepTests
Add more test cases
Remove Heap.IsTemporaryPointer()
Fix regression
Remove GCDisposeObject() in GCMarkAndSweep()
Add MetaData field to Heap and refactor Heap members
Add thisptr as gc root
Add compilation flag to switch gc strategy
Save gc root symbol name for debugging
Not seeting property for deleted heap element
Remove duplicate code and refactoring RuntimeMemory
Further cleanup RuntimeMemory
Replace low-level stack accessing with getting property from stackframe
merge master, resolve conflict