[PATCH bpf-next v3] bpf: btf: include linux/types.h for u32

[Dmitrii Bundin <dmitrii.bundin.a@xxxxxxxxx>]

Inclusion of the header linux/btf_ids.h relies on indirect inclusion of
the header linux/types.h. Including it directly on the top level helps
to avoid potential problems if linux/types.h hasn't been included
before.

The main motiviation to introduce this it is to avoid similar problems that
was shown up in the bpf tool where GNU libc indirectly pulls
linux/types.h causing compile error of the form:

   error: unknown type name 'u32'
                             u32 cnt;
                             ^~~

The bpf tool compile error was fixed at 62248b22d01e96a4d669cde0d7005bd51ebf9e76

Fixes: 9707ac4fe2f5 ("tools/resolve_btfids: Refactor set sorting with types from btf_ids.h")

Signed-off-by: Dmitrii Bundin <dmitrii.bundin.a@xxxxxxxxx>
---

Changes in v2: Add bpf-next to the subject
Changes in v3: Add Fixes tag and bpf tool commit reference

 include/linux/btf_ids.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
index e24aabfe8ecc..c0e3e1426a82 100644
--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h
@@ -3,6 +3,8 @@
 #ifndef _LINUX_BTF_IDS_H
 #define _LINUX_BTF_IDS_H
 
+#include <linux/types.h> /* for u32 */
+
 struct btf_id_set {
 	u32 cnt;
 	u32 ids[];
-- 
2.34.1