Remove test references to absl::SharedBitGen, which was never part of

the open source release. This was only used in tests that never ran
as part in the open source release.

PiperOrigin-RevId: 636167506
Change-Id: Iafc33bd768307fe9ee77b181369635012abf2245

absl/synchronization/internal/kernel_timeout_test.cc

@@ -36,7 +36,7 @@ extern "C" int __clock_gettime(clockid_t c, struct timespec* ts);
 extern "C" int clock_gettime(clockid_t c, struct timespec* ts) {
   if (c == CLOCK_MONOTONIC &&
       !absl::synchronization_internal::KernelTimeout::SupportsSteadyClock()) {
-    absl::SharedBitGen gen;
+    thread_local absl::BitGen gen;  // NOLINT
     ts->tv_sec = absl::Uniform(gen, 0, 1'000'000'000);
     ts->tv_nsec = absl::Uniform(gen, 0, 1'000'000'000);
     return 0;

absl/synchronization/internal/waiter_test.cc

@@ -44,7 +44,7 @@ extern "C" int __clock_gettime(clockid_t c, struct timespec* ts);
 extern "C" int clock_gettime(clockid_t c, struct timespec* ts) {
   if (c == CLOCK_MONOTONIC &&
       !absl::synchronization_internal::KernelTimeout::SupportsSteadyClock()) {
-    absl::SharedBitGen gen;
+    thread_local absl::BitGen gen;  // NOLINT
     ts->tv_sec = absl::Uniform(gen, 0, 1'000'000'000);
     ts->tv_nsec = absl::Uniform(gen, 0, 1'000'000'000);
     return 0;