Fix offset in removeThread() function so that float registers start freeing up

Fix offset in removeThread() function so that float registers start freeing up
from the right point (#32 usually) instead of restarting at 0 and double-freeing.

Commented out assert line in free_list.hh that will check for when double-free condition
goes bad.

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extra : convert_revision : 08d5f9b6a874736e487d101e85c22aaa67bf59ae