Fix DragonFlyBSD build

Reviewers: rnk, thakis

Reviewed By: krytarowski

Differential Revision: https://reviews.llvm.org/D54363

llvm-svn: 346577
diff --git a/llvm/lib/Support/Unix/Path.inc b/llvm/lib/Support/Unix/Path.inc
index 02b7c25..e36e389 100644
--- a/llvm/lib/Support/Unix/Path.inc
+++ b/llvm/lib/Support/Unix/Path.inc
@@ -38,6 +38,8 @@
 #ifdef __APPLE__
 #include <mach-o/dyld.h>
 #include <sys/attr.h>
+#elif defined(__DragonFly__)
+#include <sys/mount.h>
 #endif
 
 // Both stdio.h and cstdio are included via different paths and
@@ -83,7 +85,7 @@
 #define STATVFS_F_FRSIZE(vfs) static_cast<uint64_t>(vfs.f_bsize)
 #endif
 
-#if defined(__NetBSD__) || defined(__GNU__)
+#if defined(__NetBSD__) || defined(__DragonFly__) || defined(__GNU__)
 #define STATVFS_F_FLAG(vfs) (vfs).f_flag
 #else
 #define STATVFS_F_FLAG(vfs) (vfs).f_flags