Fix ESTABLISH-THREAD-FOOTHOLD when called with a closure.
Fix ESTABLISH-THREAD-FOOTHOLD when called with a closure.

FORCE-CALL-ON-THREAD was not respecting the function calling convention
and closures were not be passed their environments.

rvedam/Mezzano,froggey/Mezzano,froggey/Mezzano,rvedam/Mezzano