xlist and xoset header files

[Ralf Wildenhues]

The xlist and the xoset modules fail to gnulib --test due to missing
headers; the patch below fixes that.  OK to commit?

Thanks,
Ralf

        Include missing headers for xlist and xoset modules.
        * modules/xlist (Files): Add lib/gl_list.h.
        * modules/xoset (Files): Add lib/gl_oset.h.

diff --git a/modules/xlist b/modules/xlist
index 4bac28f..3cee4c6 100644
--- a/modules/xlist
+++ b/modules/xlist
@@ -4,6 +4,7 @@ Abstract sequential list data type, with out-of-memory checking.
 Files:
 lib/gl_xlist.h
 lib/gl_xlist.c
+lib/gl_list.h
 m4/gl_list.m4
 
 Depends-on:
diff --git a/modules/xoset b/modules/xoset
index ba4eab7..2acaab7 100644
--- a/modules/xoset
+++ b/modules/xoset
@@ -4,6 +4,7 @@ Abstract ordered set data type, with out-of-memory checking.
 Files:
 lib/gl_xoset.h
 lib/gl_xoset.c
+lib/gl_oset.h
 m4/gl_list.m4
 
 Depends-on: