kernel32: Don't save the signal mask in sigsetjmp.

This shouldn't be needed anymore now that exceptions are not handled
on the signal stack, and signal mask handling is broken on Mac OS.

dlls/kernel32/fiber.c

@@ -188,7 +188,7 @@ void WINAPI SwitchToFiber( LPVOID fiber )
     /* stack_allocation and stack_base never change */
 
     /* FIXME: should save floating point context if requested in fiber->flags */
-    if (!sigsetjmp( current_fiber->jmpbuf, 1 ))
+    if (!sigsetjmp( current_fiber->jmpbuf, 0 ))
     {
         NtCurrentTeb()->Tib.u.FiberData   = new_fiber;
         NtCurrentTeb()->Tib.ExceptionList = new_fiber->except;

include/wine/exception.h

@@ -94,7 +94,7 @@
              __f.frame.Handler = __wine_exception_handler; \
              __f.u.filter = (func); \
              __wine_push_frame( &__f.frame ); \
-             if (sigsetjmp( __f.jmp, 1 )) { \
+             if (sigsetjmp( __f.jmp, 0 )) { \
                  const __WINE_FRAME * const __eptr __attribute__((unused)) = &__f; \
                  do {