in make.conf or src.conf.
- When GPT is enabled (which it is by default), use memory above 1 MB and
leave the memory from the end of the bss to the end of the 640k window
purely for the stack. The loader has grown and now it is much more
common for the heap and stack to grow into each other when both are
located in the 640k window.
PR: kern/129526
MFC after: 1 week
6e59eb9097