[6.4.0] Bump c++ standard to c++14 per default (#19794)

Fixes: #18181.

Closes: #18280.

Closes #18280.

PiperOrigin-RevId: 530246609
Change-Id: I6b49d1bd827e98ca65db87c34c1bb13106ffc232 (cherry picked from
commit 978cd23)

Co-authored-by: David Ostrovsky <david@ostrovsky.org>

tools/cpp/bsd_cc_toolchain_config.bzl

@@ -160,7 +160,7 @@ def _impl(ctx):
             ),
             flag_set(
                 actions = all_cpp_compile_actions + [ACTION_NAMES.lto_backend],
-                flag_groups = [flag_group(flags = ["-std=c++0x"])],
+                flag_groups = [flag_group(flags = ["-std=c++14"])],
             ),
         ],
     )

tools/cpp/unix_cc_configure.bzl

@@ -1,6 +1,6 @@
 # pylint: disable=g-bad-file-header
 # Copyright 2016 The Bazel Authors. All rights reserved.
-#
+
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
@@ -409,7 +409,7 @@ def configure_unix_toolchain(repository_ctx, cpu_value, overriden_tools):
     cxx_opts = split_escaped(get_env_var(
         repository_ctx,
         "BAZEL_CXXOPTS",
-        "-std=c++0x",
+        "-std=c++14",
         False,
     ), ":")
 

tools/cpp/windows_cc_toolchain_config.bzl

@@ -1203,7 +1203,7 @@ def _impl(ctx):
                         ACTION_NAMES.lto_backend,
                         ACTION_NAMES.clif_match,
                     ],
-                    flag_groups = [flag_group(flags = ["-std=gnu++0x"])],
+                    flag_groups = [flag_group(flags = ["-std=gnu++14"])],
                 ),
             ],
         )