freebsd: allow building tcc which targets windows
freebsd: allow building tcc which targets windows

Currently tcc doesn't have a compile-time config indicating that the target
is freebsd, and as a result, the tcc binary adds freebsh stuff to elf headers
if the compile-time (of tcc) *host* is freebsd.

Test also that the target is not PE while generating an elf header.

This still likely fails (but untested) when tcc targets other non-freebsd
systems on a freebsd system, but for now fix it only when targetting windows.

mirror/tinycc,code4game/tinycc,code4game/tinycc,mingodad/tinycc,avih/tinycc,mirror/tinycc,code4game/tinycc,avih/tinycc,avih/tinycc,mingodad/tinycc,avih/tinycc,mingodad/tinycc,mirror/tinycc,mirror/tinycc,mingodad/tinycc