Add <glob.h>.

This is the FreeBSD implementation, plus some tests. The FreeBSD
implementation includes the GNU extensions and seems to be what
iOS is using too, which should provide bug compatibility for app
developers.

The code unfortunately uses a lot of stack, and uses FreeBSD locale
implementation that we don't have, but it does seem better maintained
than the other BSDs.

Bug: http://b/29251134
Test: ran tests
Change-Id: Ie477b45e42a6df1319b25712098519d2b33adf67
diff --git a/libc/libc.arm.map b/libc/libc.arm.map
index 5018951..50e0e7b 100644
--- a/libc/libc.arm.map
+++ b/libc/libc.arm.map
@@ -1323,6 +1323,8 @@
     __freading; # future
     __fwriting; # future
     getlogin_r; # future
+    glob; # future
+    globfree; # future
     hcreate; # future
     hcreate_r; # future
     hdestroy; # future