[coroutines] Implement unhandled_exception changes.

Summary:
This patch adopts the recent changes that renamed `set_exception(exception_pointer)` to `unhandled_exception()`. 

Additionally `unhandled_exception()` is now required, and so an error is emitted when exceptions are enabled but the promise type does not provide the member.
When exceptions are disabled a warning is emitted instead of an error, The warning notes that the `unhandled_exception()` function is required when exceptions are enabled.

Reviewers: rsmith, GorNishanov, aaron.ballman, majnemer

Reviewed By: GorNishanov

Subscribers: mehdi_amini, cfe-commits

Differential Revision: https://reviews.llvm.org/D30859

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@298565 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 37 insertions, 0 deletions

diff --git a/test/SemaCXX/Inputs/std-coroutine.h b/test/SemaCXX/Inputs/std-coroutine.h
new file mode 100644
index 0000000000..7a424f1e99
--- /dev/null
+++ b/test/SemaCXX/Inputs/std-coroutine.h
@@ -0,0 +1,37 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin9 %s -std=c++14 -fcoroutines-ts -fsyntax-only -Wignored-qualifiers -Wno-error=return-type -verify -fblocks -Wno-unreachable-code -Wno-unused-value
+#ifndef STD_COROUTINE_H
+#define STD_COROUTINE_H
+
+namespace std {
+namespace experimental {
+
+template <class Ret, typename... T>
+struct coroutine_traits { using promise_type = typename Ret::promise_type; };
+
+template <class Promise = void>
+struct coroutine_handle {
+  static coroutine_handle from_address(void *);
+};
+template <>
+struct coroutine_handle<void> {
+  template <class PromiseType>
+  coroutine_handle(coroutine_handle<PromiseType>);
+  static coroutine_handle from_address(void *);
+};
+
+struct suspend_always {
+  bool await_ready() { return false; }
+  void await_suspend(coroutine_handle<>) {}
+  void await_resume() {}
+};
+
+struct suspend_never {
+  bool await_ready() { return true; }
+  void await_suspend(coroutine_handle<>) {}
+  void await_resume() {}
+};
+
+} // namespace experimental
+} // namespace std
+
+#endif // STD_COROUTINE_H