When a local is optimized out, the proc shouldn't allocate stack space for it

[dplassgit]

Original source:

f:proc:bool { a='abc' b=null c=a == b return c} println f()

IL code:

goto __after_proc_f_1
_f:
f() {
return false
end f
__after_proc_f_1:
__temp3 = f()
printf("%s", __temp3)
printf("%s", \"\n\")
exit(0)

Used to have 3 local variables in f() and so it still allocates space:

  sub RSP, 32  ; space for locals

[dplassgit]

This is actually blocked on #62