Kirill 'Big K' Katsnelson writes:
Is there any use for this function at all? What is the concept of
"last allocated byte", from the lisp point of view?
It just tells you roughly where the heap ends, at least under
UNIX. If the value returned by memory-limit keeps rising during
an operation that should not be consuming memory, example
then we have a leak. As the docstring says, it's just a debugging
aid. I can't imagine that code relies on it. #ifdef it out if
it makes no sense under Windows.