Don't compile primitive functions that we don't need about lisp HOT 3 CLOSED

Backstory: the reason that we don't need to emit primitives that appear only in the head position of a list is because for performance reasons we inline those calls. This leads to a very substantial performance increase.

Something like calling fib(40) goes from something that takes painfully long to something that happens in under a second with this optimization.

from lisp.

As an example, in the following program we only really need to compile add and sub as they are the only primitives that appear.

(let pair (cons add sub))
((car pair) ((cdr pair) 5 4) 41)

from lisp.

For some perspective on why this would be valuable, here's some timing information from the fib test:

parse                             254.15µs
emit alloc                        1.50ms
emit primitives                   506.58ms
symbol renaming pass              65.84µs
data collection pass              4.37µs
data replacement pass             3.94µs
data creation                     1.47µs
function collection pass          17.24µs
free variable analysis            77.15µs
function replacement pass         16.09µs
free variable annotation          9.00µs
procedure compilation             162.40ms
lust_entry compilation            15.60ms
program execution                 2.15s
total                             2.84s

Compiling primitives is by far the slowest operation.

from lisp.