Commit 
ff8577f64987a898e1dc5eb6afb66a404fb7bb16 added a call to
gdb_abspath in bsd-kvm.c, but doesn't include its header file.
This commit fixes that.
gdb/ChangeLog:
2019-12-17  Christian Biesinger  <cbiesinger@google.com>
	* bsd-kvm.c: Include gdbsupport/pathstuff.h.
Change-Id: I647c3620d8ae978ae27c38dbe0b3347a97c5bfc2
+2019-12-17  Christian Biesinger  <cbiesinger@google.com>
+
+       * bsd-kvm.c: Include gdbsupport/pathstuff.h.
+
 2019-12-17  Simon Marchi  <simon.marchi@polymtl.ca>
 
        * tui/tui-layout.h (class tui_layout_base): Add virtual
 
 #include "gdbcore.h"
 #include "inferior.h"          /* for get_exec_file */
 #include "gdbthread.h"
+#include "gdbsupport/pathstuff.h"
 
 #include <fcntl.h>
 #include <kvm.h>