fix internal clang errors on Windows

Summary: Fix clang internal error on Windows.

Reviewed By: yfeldblum

Differential Revision: D26994868

fbshipit-source-id: 97fe79231fcbfc0fc6712626dee8e1d570dd0dd6

folly/experimental/coro/Collect-inl.h

@@ -507,8 +507,12 @@ auto collectAllTryRange(InputRange awaitables)
             executor.get_alias(),
             co_withCancellation(cancelToken, std::move(semiAwaitable))));
       }
+// This causes "Instruction does not dominate all uses!" internal compiler
+// error on Windows with Clang.
+#if !(defined(_WIN32) && defined(__clang__))
     } catch (const std::exception& ex) {
       result.emplaceException(std::current_exception(), ex);
+#endif
     } catch (...) {
       result.emplaceException(std::current_exception());
     }

folly/experimental/coro/Task.h

@@ -360,8 +360,11 @@ class FOLLY_NODISCARD TaskWithExecutor {
   detail::InlineTaskDetached startImpl(TaskWithExecutor task, F cb) {
     try {
       cb(co_await folly::coro::co_awaitTry(std::move(task)));
+// This causes clang internal error on Windows.
+#if !(defined(_WIN32) && defined(__clang__))
     } catch (const std::exception& e) {
       cb(Try<StorageType>(exception_wrapper(std::current_exception(), e)));
+#endif
     } catch (...) {
       cb(Try<StorageType>(exception_wrapper(std::current_exception())));
     }
@@ -371,8 +374,11 @@ class FOLLY_NODISCARD TaskWithExecutor {
   detail::InlineTaskDetached startInlineImpl(TaskWithExecutor task, F cb) {
     try {
       cb(co_await InlineTryAwaitable{std::exchange(task.coro_, {})});
+// This causes clang internal error on Windows.
+#if !(defined(_WIN32) && defined(__clang__))
     } catch (const std::exception& e) {
       cb(Try<StorageType>(exception_wrapper(std::current_exception(), e)));
+#endif
     } catch (...) {
       cb(Try<StorageType>(exception_wrapper(std::current_exception())));
     }