Document that absl::linked_hash_map and absl::linked_hash_set do not guarantee exception safety.

PiperOrigin-RevId: 953514931
Change-Id: I2ae4a64144c3251c5d444ee5077f5bb4969f4fc9

absl/container/linked_hash_map.h

diff --git a/absl/container/linked_hash_map.h b/absl/container/linked_hash_map.h
index 7ebeaf7..6d0e320 100644
--- a/absl/container/linked_hash_map.h
+++ b/absl/container/linked_hash_map.h
@@ -21,6 +21,7 @@
 // order.
 //
 // This class is thread-compatible.
+// This class is NOT exception-safe.
 //
 // Iterators point into the list and should be stable in the face of
 // mutations, except for an iterator pointing to an element that was just

absl/container/linked_hash_set.h

diff --git a/absl/container/linked_hash_set.h b/absl/container/linked_hash_set.h
index cda21d6..7fe0adc 100644
--- a/absl/container/linked_hash_set.h
+++ b/absl/container/linked_hash_set.h
@@ -21,6 +21,7 @@
 // order.
 //
 // This class is thread-compatible.
+// This class is NOT exception-safe.
 //
 // Iterators point into the list and should be stable in the face of
 // mutations, except for an iterator pointing to an element that was just