At the moment each instance extension needs special handling
in 6+ places when added to the Vulkan backend. This is very
error-prone and makes it difficult to do changes in how they
are extensions are handled.
This CL makes instance extensions linked with an enum class
and a bitset to know which are available (instead of individual
booleans). A table of known extensions with more information like
`versionPromoted` so that they can be handled programmatically.
Bug: dawn:457
Change-Id: I266deb730eb2b7f3ab0ee7ada1b06ff9748a60e4
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/22940
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>