include: add 128-bit integer types to linux/types.h

Linux 7.3 declares the fpsimd registers in the arm64 sigcontext as
__u128 instead of __uint128_t, see kernel commit d4bf9e08d412 ("arm64:
uapi: Use __u128 instead of __uint128_t in UAPI headers"). The private
linux/types.h in include/ shadows the kernel's linux/types.h while
building libbpf, so with glibc, whose signal.h pulls in
asm/sigcontext.h, the build fails with an unknown type name __u128.
Add the __s128 and __u128 typedefs as the kernel's uapi and tools
headers define them.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

include/linux/types.h

@@ -12,6 +12,11 @@
 #include <asm/types.h>
 #include <asm/posix_types.h>
 
+#ifdef __SIZEOF_INT128__
+typedef __signed__ __int128 __s128 __attribute__((aligned(16)));
+typedef unsigned __int128 __u128 __attribute__((aligned(16)));
+#endif
+
 #define __bitwise__
 #define __bitwise __bitwise__