perf auxtrace: Drop legacy __sync functions

The main purpose for using __sync built-in functions is to support
compat mode for 32-bit perf with 64-bit kernel.  But using these
built-in functions might cause potential issues.

__sync functions originally support Intel Itanium processoer [1] but it
cannot promise to support all 32-bit archs.  Now these functions have
become the legacy functions.

Considering __sync functions cannot really fix the 64-bit value
atomicity on 32-bit archs, thus this patch drops __sync functions.

Credits to Peter for detailed analysis.

[1] https://gcc.gnu.org/onlinedocs/gcc/_005f_005fsync-Builtins.html#g_t_005f_005fsync-Builtins

Suggested-by: Peter Zijlstra <[email protected]>
Signed-off-by: Leo Yan <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Daniel Díaz <[email protected]>
Cc: Frank Ch. Eigler <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Poirier <[email protected]>
Cc: Michael Petlan <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sedat Dilek <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

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