Update to v6.6 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-6.6

Test: Builds and bionic unit tests pass on raven.
Test: Able to log in to an Android GO 32 bit device.
Change-Id: Ib5ff5a23f382721d98d1e428a295c6794b190d8d
diff --git a/libc/kernel/uapi/linux/stddef.h b/libc/kernel/uapi/linux/stddef.h
index 6bc6925..98968a2 100644
--- a/libc/kernel/uapi/linux/stddef.h
+++ b/libc/kernel/uapi/linux/stddef.h
@@ -23,5 +23,12 @@
 #define __always_inline inline
 #endif
 #define __struct_group(TAG,NAME,ATTRS,MEMBERS...) union { struct { MEMBERS } ATTRS; struct TAG { MEMBERS } ATTRS NAME; }
+#ifdef __cplusplus
+#define __DECLARE_FLEX_ARRAY(T,member) T member[0]
+#else
 #define __DECLARE_FLEX_ARRAY(TYPE,NAME) struct { struct { } __empty_ ##NAME; TYPE NAME[]; }
 #endif
+#ifndef __counted_by
+#define __counted_by(m)
+#endif
+#endif