Copy nodes without pointers to end of heap during garbage collection
As in the native runtime system, we can copy nodes without pointers to the end of the other semispace. That would mean that they do not have to be checked for child nodes, which should be slightly faster. Furthermore, the tests for nodes without pointer arguments can be removed from the code that walks through the copied nodes.
This has to be done in two places:
- C garbage collector
- Wasm garbage collector