Disable buffering of test output to keep more information in case of a
crash.

include/wine/test.h

diff --git a/include/wine/test.h b/include/wine/test.h
index d48396e..cb3af8a 100644
--- a/include/wine/test.h
+++ b/include/wine/test.h
@@ -313,6 +313,8 @@
 {
     char *p;
 
+    setvbuf (stdout, NULL, _IONBF, 0);
+
     winetest_argc = argc;
     winetest_argv = argv;