tree a474a12423cb60a61e30ec03a3a9970e64ece23e
parent 9df63a8beaae53802109346f0a20328140a7cb8e
author Greg Falcon <gfalcon@google.com> 1652893274 -0700
committer Copybara-Service <copybara-worker@google.com> 1652893317 -0700

Replace direct uses of __builtin_prefetch from SwissTable with the wrapper functions.

Add a new (internal) feature test macro to detect whether the wrappers are no-ops on a given platform.

Note that one-arg __builtin_prefetch(x) is equivalent to __builtin_prefetch(x, 0, 3), per `man BUILTIN_PREFETCH(3)` and gcc docs.

PiperOrigin-RevId: 449508660
Change-Id: I144e750205eec0c956d8dd62bc72e10bdb87c4f7