* Cleanup, remove lib/system/allocators.nim. seqs_v2 and strs_v2 now use
allocShared0 by default.
* Fixed -d:useMalloc allocShared / reallocShared / deallocShared. These now use the alloc/dealloc/realloc implementation that also takes care of zeroing memory at realloc.
* Removed debug printfs
* Removed unpairedEnvAllocs() from tests/destructor/tnewruntime_misc
* More mmdisp cleanups. The shared allocators do not need to zero memory or throw since the regular ones already do that
* Introduced realloc0 and reallocShared0, these procs are now used by
strs_v2 and seqs_v2. This also allowed the -d:useMalloc allocator to
drop the extra header with allocation length.
* Moved strs_v2/seqs_v2 'allocated' flag into 'cap' field
* Added 'getAllocStats()' to get low level alloc/dealloc counters. Enable with -d:allocStats
* *allocShared implementations for boehm and go allocators now depend on the proper *allocImpl procs
This implements "deterministic" exception handling for Nim based on goto instead of setjmp. This means raising an exception is much cheaper than in C++'s table based implementations. Supports hard realtime systems. Default for --gc:arc and the C target because it's generally a good idea and arc is all about deterministic behavior.
Note: This implies that fatal runtime traps are not catchable anymore! This needs to be documented.
* first implementation of the =trace and =dispose hooks for the cycle collector
* a cycle collector for ARC: progress
* manual: the .acyclic pragma is a thing once again
* gcbench: adaptations for --gc:arc
* enable valgrind tests for the strutils tests
* testament: better valgrind support
* ARC refactoring: growable jumpstacks
* ARC cycle detector: non-recursive algorithm
* moved and renamed core/ files back to system/
* refactoring: --gc:arc vs --gc:orc since 'orc' is even more experimental and we want to ship --gc:arc soonish
* cursors: first implementation
* added currently failing test
* .cursor works for doubly linked lists
* make -d:useMalloc work again
* added code to nil out refs in a destructor
* it's now called --gc:arc
* renderer.nim: render nkBreakState properly
* make simple closure iterators work without leaking
