Revert "[coroutines] Add std::experimental::task<T> type"

This revision is causing build and test failures, such as
http://lab.llvm.org:8011/builders/libcxx-libcxxabi-libunwind-armv8-linux/builds/648/steps/test.libcxx/logs/stdio,
so I'll revert it.

llvm-svn: 357023

1 files changed, 0 insertions, 57 deletions

diff --git a/libcxx/test/std/experimental/task/task.lifetime/task_parameter_lifetime.pass.cpp b/libcxx/test/std/experimental/task/task.lifetime/task_parameter_lifetime.pass.cpp
deleted file mode 100644
index bc1bd432244..00000000000
--- a/libcxx/test/std/experimental/task/task.lifetime/task_parameter_lifetime.pass.cpp
+++ /dev/null
@@ -1,57 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++98, c++03, c++11, c++14
-
-#include <experimental/task>
-#include <cassert>
-
-#include "../counted.hpp"
-#include "../sync_wait.hpp"
-
-DEFINE_COUNTED_VARIABLES();
-
-void test_parameter_lifetime()
-{
-  counted::reset();
-
-  auto f = [](counted c) -> std::experimental::task<std::size_t>
-  {
-    co_return c.id();
-  };
-
-  {
-    auto t = f({});
-
-    assert(counted::active_instance_count() == 1);
-    assert(counted::copy_constructor_count() == 0);
-    assert(counted::move_constructor_count() <= 2); // Ideally <= 1
-
-    auto id = sync_wait(t);
-    assert(id == 1);
-
-    assert(counted::active_instance_count() == 1);
-    assert(counted::copy_constructor_count() == 0);
-
-    // We are relying on C++17 copy-elision when passing the temporary counter
-    // into f(). Then f() must move the parameter into the coroutine frame by
-    // calling the move-constructor. This move could also potentially be
-    // elided by the
-    assert(counted::move_constructor_count() <= 1);
-  }
-
-  assert(counted::active_instance_count() == 0);
-}
-
-int main()
-{
-  test_parameter_lifetime();
-  return 0;
-}