File stubdom-have-iovec.patch of Package xen.21118

Because of commit 76eb7cef6b84ca804f4db340e23ad9c501767c32
xc_private.h now contains a definition of iovec. This conflicts
when building qemu traditional xen_platform.c which includes
hw.h which includes qemu-common.h which already has a definition
of iovec
Index: xen-4.12.0-testing/tools/libxc/xc_private.h
===================================================================
--- xen-4.12.0-testing.orig/tools/libxc/xc_private.h
+++ xen-4.12.0-testing/tools/libxc/xc_private.h
@@ -50,6 +50,8 @@
 #endif
 
 #if defined(__MINIOS__)
+#ifndef HAVE_IOVEC
+#define HAVE_IOVEC
 /*
  * MiniOS's libc doesn't know about sys/uio.h or writev().
  * Declare enough of sys/uio.h to compile.
@@ -58,6 +60,7 @@ struct iovec {
     void *iov_base;
     size_t iov_len;
 };
+#endif
 #else
 #include <sys/uio.h>
 #endif