CMD-Buf supported queue properties

[EwanC]

Updates to the command-buffer emulation layer to support changes from https://github.com/KhronosGroup/OpenCL-Docs/pull/850

Requires using https://github.com/KhronosGroup/OpenCL-Headers/pull/265 in external/OpenCL-Headers and can be used to test CTS changes from https://github.com/KhronosGroup/OpenCL-CTS/pull/2101

[bashbaug]

Thanks, this is great!

Do you want to hold off on this one until the headers changes are merged, or try to add in some #ifdefs so it'll work both with newer and older headers?

[EwanC]

Thanks, this is great!

Do you want to hold off on this one until the headers changes are merged, or try to add in some #ifdefs so it'll work both with newer and older headers?

Let's just wait for the headers to be merged, which hopefully won't be long now

[EwanC]

Headers are merged now, so this PR could be merged as-is (if approved)