ntdll: Fixed some heap allocation stalls

[Daniel Lehman]

>> Which game were you testing?

i dunno about the game, but i saw similar stalls in our software

a huge batch process that consumed about 1 GB on Windows would both run slower and eat up about 2 GB on Wine before crashing

i made a similar change to Steaphan's that not only improved performance, it brought the memory usage down to roughly what it was on Windows - and didn't crash

i was planning on submitting it at some point if i could think of a good test to validate it.  the only difference was that i added more lists, but i'd say adding more free lists definitely makes it faster

daniel