Export of internal Abseil changes

--
14d42e9d0b8aed0c0f00900cd6fd790908930de5 by Gennadiy Rozental <rogeeff@google.com>:

Fix gcc ci build command for LTS

PiperOrigin-RevId: 331543198

--
f1655ec91a4ad656dd1100cf2e134d08941278ca by Abseil Team <absl-team@google.com>:

Consistently document size_type return value of all map/set types.

PiperOrigin-RevId: 331528359
GitOrigin-RevId: 14d42e9d0b8aed0c0f00900cd6fd790908930de5
Change-Id: I33ebba4acb3e5918e4e112f03c81aba529dcd0b4

absl/container/btree_map.h

@@ -185,7 +185,7 @@ class btree_map
   // template <typename K> size_type erase(const K& key):
   // template <typename K> size_type erase(const K& key):
   //
   //
   //   Erases the element with the matching key, if it exists, returning the
   //   Erases the element with the matching key, if it exists, returning the
-  //   number of elements erased.
+  //   number of elements erased (0 or 1).
   using Base::erase;
   using Base::erase;
 
 
   // btree_map::insert()
   // btree_map::insert()

absl/container/btree_set.h

@@ -183,7 +183,7 @@ class btree_set
   // template <typename K> size_type erase(const K& key):
   // template <typename K> size_type erase(const K& key):
   //
   //
   //   Erases the element with the matching key, if it exists, returning the
   //   Erases the element with the matching key, if it exists, returning the
-  //   number of elements erased.
+  //   number of elements erased (0 or 1).
   using Base::erase;
   using Base::erase;
 
 
   // btree_set::insert()
   // btree_set::insert()

absl/container/flat_hash_map.h

@@ -234,7 +234,8 @@ class flat_hash_map : public absl::container_internal::raw_hash_map<
   //
   //
   // size_type erase(const key_type& key):
   // size_type erase(const key_type& key):
   //
   //
-  //   Erases the element with the matching key, if it exists.
+  //   Erases the element with the matching key, if it exists, returning the
+  //   number of elements erased (0 or 1).
   using Base::erase;
   using Base::erase;
 
 
   // flat_hash_map::insert()
   // flat_hash_map::insert()

absl/container/flat_hash_set.h

@@ -227,7 +227,8 @@ class flat_hash_set
   //
   //
   // size_type erase(const key_type& key):
   // size_type erase(const key_type& key):
   //
   //
-  //   Erases the element with the matching key, if it exists.
+  //   Erases the element with the matching key, if it exists, returning the
+  //   number of elements erased (0 or 1).
   using Base::erase;
   using Base::erase;
 
 
   // flat_hash_set::insert()
   // flat_hash_set::insert()

absl/container/node_hash_map.h

@@ -225,7 +225,8 @@ class node_hash_map
   //
   //
   // size_type erase(const key_type& key):
   // size_type erase(const key_type& key):
   //
   //
-  //   Erases the element with the matching key, if it exists.
+  //   Erases the element with the matching key, if it exists, returning the
+  //   number of elements erased (0 or 1).
   using Base::erase;
   using Base::erase;
 
 
   // node_hash_map::insert()
   // node_hash_map::insert()

absl/container/node_hash_set.h

@@ -217,7 +217,8 @@ class node_hash_set
   //
   //
   // size_type erase(const key_type& key):
   // size_type erase(const key_type& key):
   //
   //
-  //   Erases the element with the matching key, if it exists.
+  //   Erases the element with the matching key, if it exists, returning the
+  //   number of elements erased (0 or 1).
   using Base::erase;
   using Base::erase;
 
 
   // node_hash_set::insert()
   // node_hash_set::insert()

ci/linux_gcc-latest_libstdcxx_bazel.sh

@@ -75,7 +75,7 @@ for std in ${STD}; do
         ${DOCKER_CONTAINER} \
         ${DOCKER_CONTAINER} \
         /bin/sh -c "
         /bin/sh -c "
           cp -r /abseil-cpp-ro/* /abseil-cpp/
           cp -r /abseil-cpp-ro/* /abseil-cpp/
-          if [[ -n \"${ALTERNATE_OPTIONS:-}\" ]]; then
+          if [ -n \"${ALTERNATE_OPTIONS:-}\" ]; then
             cp ${ALTERNATE_OPTIONS:-} absl/base/options.h || exit 1
             cp ${ALTERNATE_OPTIONS:-} absl/base/options.h || exit 1
           fi
           fi
           /usr/local/bin/bazel test ... \
           /usr/local/bin/bazel test ... \