The C code now has garbage collection. It now uses negative memory
for storing cons cells. Function arguments have been inlined since
undefined evaluation order shouldn't matter since it is immutable.
Compiler warnings have been turned off so we can use traditional C
The flag bit is now removed from atoms in favor of the sign bit.
That let us remove shifts. It also means NIL can be zero, which
freed up the %cx register. Using %cx to call Eval saved 2 bytes.
Saved six bytes removing bss memset as it's not needed anymore.
