selftests/rseq: Replace glibc-specific __GNUC_PREREQ with portable check

Building the rseq selftests against musl libc fails because musl's
<features.h> does not provide the glibc-specific __GNUC_PREREQ macro:

  error: missing binary operator before token '('

Replace __GNUC_PREREQ(11, 1) with an equivalent check using __GNUC__
and __GNUC_MINOR__ directly.  This pattern is portable across all C
library implementations and is already used elsewhere in the tools/
tree (e.g., tools/include/linux/string.h).

This also allows removing the #include <features.h>, which was only
needed for __GNUC_PREREQ.

Fixes: 886ddfba933f ("selftests/rseq: Introduce thread pointer getters")
Signed-off-by: Hisam Mehboob <hisamshar@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260618193724.589113-2-hisamshar@gmail.com

0 files changed, 0 insertions, 0 deletions