With any luck, this will clean up errors where we detect that
REG_{EIP,RIP} is present in autoconf, but when we go to include it,
it isn't there.
#ifdef HAVE_SIGNAL_H
#include <signal.h>
#endif
-#ifdef HAVE_UCONTEXT_H
-#include <ucontext.h>
-#endif
-#ifdef HAVE_SYS_UCONTEXT_H
+
+#ifdef HAVE_CYGWIN_SIGNAL_H
+#include <cygwin/signal.h>
+#elif HAVE_SYS_UCONTEXT_H
#include <sys/ucontext.h>
+#elif defined(HAVE_UCONTEXT_H)
+#include <ucontext.h>
#endif
#if defined(HAVE_EXECINFO_H) && defined(HAVE_BACKTRACE) && \