Avoid referencing `PolicyFunctions` in raw_hash_set move operations unless generations are enabled.

`common().annotate_for_bug_detection_on_move(that.common(), GetPolicyFunctions())` evaluates `GetPolicyFunctions()` as an argument even though the callee only uses it when `SwisstableGenerationsEnabled()`. This keeps the per-table `PolicyFunctions` instance referenced from every move constructor/assignment. Wrap the call in a member `annotate_for_bug_detection_on_move(that)` that only references `GetPolicyFunctions()` under `if constexpr (SwisstableGenerationsEnabled())`.

PiperOrigin-RevId: 1009575588

absl/container/internal/hashtablez_sampler.h

diff --git a/absl/container/internal/hashtablez_sampler.h b/absl/container/internal/hashtablez_sampler.h
index 9e9a47c..628acf6 100644
--- a/absl/container/internal/hashtablez_sampler.h
+++ b/absl/container/internal/hashtablez_sampler.h
@@ -247,9 +247,11 @@
 // It is useful to avoid sampling attempts and sampling delays in tests.
 void TestOnlyRefreshSamplingStateForCurrentThread();
 
-// Returns a sampling handle.
-inline HashtablezInfoHandle Sample(size_t inline_element_size, size_t key_size,
-                                   size_t value_size, uint16_t soo_capacity) {
+// Returns a sampling handle. For use in tests only: `raw_hash_set` calls
+// `ShouldSampleNextTable()` and `ForcedTrySample()` directly.
+inline HashtablezInfoHandle SampleForTesting(size_t inline_element_size,
+                                             size_t key_size, size_t value_size,
+                                             uint16_t soo_capacity) {
   if (ABSL_PREDICT_TRUE(!ShouldSampleNextTable())) {
     return HashtablezInfoHandle(nullptr);
   }

absl/container/internal/hashtablez_sampler_test.cc

diff --git a/absl/container/internal/hashtablez_sampler_test.cc b/absl/container/internal/hashtablez_sampler_test.cc
index 0d863a8..b61976d 100644
--- a/absl/container/internal/hashtablez_sampler_test.cc
+++ b/absl/container/internal/hashtablez_sampler_test.cc
@@ -332,10 +332,10 @@
   double sample_rate = 0.0;
   for (int i = 0; i < 1000000; ++i) {
     HashtablezInfoHandle h =
-        Sample(test_element_size,
-               /*key_size=*/test_key_size, /*value_size=*/test_value_size,
-
-               /*soo_capacity=*/0);
+        SampleForTesting(test_element_size,
+                         /*key_size=*/test_key_size,
+                         /*value_size=*/test_value_size,
+                         /*soo_capacity=*/0);
 
     ++total;
     if (h.IsSampled()) {

absl/container/internal/raw_hash_set.h

diff --git a/absl/container/internal/raw_hash_set.h b/absl/container/internal/raw_hash_set.h
index b7fb4d1..658c828 100644
--- a/absl/container/internal/raw_hash_set.h
+++ b/absl/container/internal/raw_hash_set.h
@@ -2897,8 +2897,7 @@
       }
     }
     that.common() = CommonFields::CreateDefault<SooEnabled()>();
-    common().annotate_for_bug_detection_on_move(that.common(),
-                                                GetPolicyFunctions());
+    annotate_for_bug_detection_on_move(that);
   }
 
   raw_hash_set(raw_hash_set&& that, const allocator_type& a)
@@ -2908,8 +2907,7 @@
         alloc_(a) {
     if (CharAlloc(a) == that.char_alloc_ref()) {
       swap_common(that);
-      common().annotate_for_bug_detection_on_move(that.common(),
-                                                  GetPolicyFunctions());
+      annotate_for_bug_detection_on_move(that);
     } else {
       move_elements_allocs_unequal(std::move(that));
     }
@@ -3761,6 +3759,15 @@
                 std::move(tmp));
   }
 
+  // Only references `GetPolicyFunctions()` when generations are enabled, so
+  // that the `PolicyFunctions` instance is not kept alive otherwise.
+  void annotate_for_bug_detection_on_move(raw_hash_set& that) {
+    if constexpr (SwisstableGenerationsEnabled()) {
+      common().annotate_for_bug_detection_on_move(that.common(),
+                                                  GetPolicyFunctions());
+    }
+  }
+
   template <bool propagate_alloc>
   raw_hash_set& assign_impl(raw_hash_set&& that) {
     // We don't bother checking for this/that aliasing. We just need to avoid
@@ -3773,8 +3780,7 @@
     CopyAlloc(char_alloc_ref(), that.char_alloc_ref(),
               std::bool_constant<propagate_alloc>());
     that.common() = CommonFields::CreateDefault<SooEnabled()>();
-    common().annotate_for_bug_detection_on_move(that.common(),
-                                                GetPolicyFunctions());
+    annotate_for_bug_detection_on_move(that);
     return *this;
   }
 
@@ -3792,8 +3798,7 @@
                                        &that.char_alloc_ref());
     }
     that.common() = CommonFields::CreateDefault<SooEnabled()>();
-    common().annotate_for_bug_detection_on_move(that.common(),
-                                                GetPolicyFunctions());
+    annotate_for_bug_detection_on_move(that);
     return *this;
   }