env: re-add support for auto-completion

Currently, only basic completion is supported (no globs), but this is
what we had previously.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/lib/qsort.c b/lib/qsort.c
index e771dcf..1cc0d31 100644
--- a/lib/qsort.c
+++ b/lib/qsort.c
@@ -16,6 +16,7 @@
  * bcc and gcc. */
 
 #include <linux/types.h>
+#include <exports.h>
 #if 0
 #include <assert.h>
 #else
@@ -67,3 +68,8 @@
 		} while (wgap);
 	}
 }
+
+int strcmp_compar(const void *p1, const void *p2)
+{
+	return strcmp(*(const char **)p1, *(const char **)p2);
+}