* libguile/Makefile.am: add new header file setjump-win.h
* libguile/continuations.h, libguile/dynstack.c, libguile/dynstack.h,
libguile/intrinsics.h, libguile/vm.h:
supply custom `setjmp` macro on Windows
Mingw implements `setjmp (env)` as a macro that expands to
_setjmp (env, faddr)
where `faddr` is set to the current frame address.
This address is then stored as first element in the jump buffer `env`.
When `longjmp` is called, it tries to unwind the stack up
to the saved address by calling `RtlUnwindEx` from MSVCRT,
which will fail, if the stack frames are interwoven with
JIT-generated code, that violate the Windows x64 calling conventions.
Thus implement the macro ourselves as
_setjmp (env, NULL)
which will toggle a code path in `longjmp` that does no unwinding.
Signed-off-by: Ludovic Courtès <ludo@gnu.org>
