This reverts commit 93b83642ee34d0092b94776728dad0117c2b72a1.
- Correct riscv32 assumption about alignment (bit of a hack).
- Fix test case where the largest_small and smallest sizes are the
same.
- Fix assertion expressions.
- Fix incorrect small size in freestore_test.
- There may only be one small size for high alignment and small
pointers (riscv32).
- Don't rely on stack alignment in FreeList test.
This reworks the free store implementation in libc's malloc to use a
dlmalloc-style binary trie of circularly linked FIFO free lists. This
data structure can be maintained in logarithmic time, but it still
permits a relatively small implementation compared to other
logarithmic-time ordered maps.
The implementation doesn't do the various bitwise tricks or
optimizations used in actual dlmalloc; it instead optimizes for
(relative) readability and minimum code size. Specific optimization can
be added as necessary given future profiling.
