On Windows, mmap() now chooses addresses transactionally. It reduces the
risk of badness when interacting with the WIN32 memory manager. We don't
throw darts anymore. There is also no more retry limit, since we recover
from mystery maps more gracefully. The subroutine for combining adjacent
maps has been rewritten for clarity. The print maps subroutine is better
This change goes to great lengths to perfect the stack overflow code. On
Windows you can now longjmp() out of a crash signal handler. Guard pages
previously weren't being restored properly by the signal handler. That's
fixed, so on Windows you can now handle a stack overflow multiple times.
Great thought has been put into selecting the perfect SIGSTKSZ constants
so you can save sigaltstack() memory. You can now use kprintf() with 512
bytes of stack available. The guard pages beneath the main stack are now
recorded in the memory manager.
This change fixes getcontext() so it works right with the %rax register.
This change introduces support for Linux-style uc_context manipulation
that's fast and works well on all supported OSes and architectures. It
also integrates with the Cosmpolitan runtime which can show backtraces
comprised of multiple stacks and fibers. See the test and example code
for further details. This will be used by Mold once it's been vendored
