Export of internal Abseil changes

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3e60f355db5afd7a864591d81a6c383b6c0a0780 by Samuel Benzaquen <sbenza@google.com>:

Internal change

PiperOrigin-RevId: 272531442

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6d189240b8cebe3a390c730de491156d03049229 by Andy Getzendanner <durandal@google.com>:

Fix AtomicHook init-order fiasco under MSVC 2019.

On this platform, constexpr static init sometimes happens after dynamic init =/.  When it does, we should not zero hook_ (overwriting the value written there by dynamic init); instead we should leave it alone.  This works even when constexpr static init goes first since all uses of AtomicHook should have static storage duration and be zero-initialized.

https://developercommunity.visualstudio.com/content/problem/336946/class-with-constexpr-constructor-not-using-static.html

PiperOrigin-RevId: 272525226

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d01b14fc06bc75b41c51976ed32e7c304ea1aab7 by Abseil Team <absl-team@google.com>:

exclude emscripten from running tests involving long doubles

PiperOrigin-RevId: 272497628
GitOrigin-RevId: 3e60f355db5afd7a864591d81a6c383b6c0a0780
Change-Id: I3c8a8f5acaf7652a06ef40cf028ef5d2e142f81b

1 files changed, 32 insertions, 0 deletions

diff --git a/absl/base/internal/atomic_hook_test_helper.h b/absl/base/internal/atomic_hook_test_helper.h
new file mode 100644
index 000000000000..44ff780d6b93
--- /dev/null
+++ b/absl/base/internal/atomic_hook_test_helper.h
@@ -0,0 +1,32 @@
+// Copyright 2017 The Abseil Authors.
+//
+// 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
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_BASE_ATOMIC_HOOK_TEST_HELPER_H_
+#define ABSL_BASE_ATOMIC_HOOK_TEST_HELPER_H_
+
+#include "absl/base/internal/atomic_hook.h"
+
+namespace absl {
+namespace atomic_hook_internal {
+
+using VoidF = void (*)();
+extern absl::base_internal::AtomicHook<VoidF> func;
+extern int default_func_calls;
+void DefaultFunc();
+void RegisterFunc(VoidF func);
+
+}  // namespace atomic_hook_internal
+}  // namespace absl
+
+#endif  // ABSL_BASE_ATOMIC_HOOK_TEST_HELPER_H_