[coroutines] PCH / Modules and coroutines do not mix. Need to add serialization/deserialization

[llvmbot]

Bugzilla Link	34004
Resolution	FIXED
Resolved on	Aug 03, 2017 09:15
Version	trunk
OS	Windows NT
Blocks	#33196
Reporter	LLVM Bugzilla Contributor
CC	@zmodem

[llvmbot]

Fixed by: https://reviews.llvm.org/D35383

Commit: https://reviews.llvm.org/rL308996

[zmodem]

Merged to 5.0 in r309954