requires -DTLSF_CONFIG_DEBUG and #+tlsf-stress to be manually added.
And also add a way to "steal" memory from the end of immobile text
space which I need for something.
And with a few related improvements:
* a finalizer gives memory back to the allocator
* code never acts as filler
* easier way of tracking text page scan start offset
TLSF (https://github.com/jserv/tlsf-bsd) is a simple malloc/free
which will be used in lieu of the current text space allocator.
Its 2-clause BSD license is compatible with SBCL's.