This lets the MSVC parser work better with FrameCapture.cpp.

Bug: angleproject:3611
Change-Id: I249106dce81a7965684caf1a835f0472b34e8963
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1804878Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Tobin Ehlis <tobine@google.com>
Commit-Queue: Jamie Madill <jmadill@chromium.org>