Add a proposal for consistently naming llvm.dx intrinsics.

[bogner]

No description provided.

[tex3d]

To be clear this was "gs" (geometry shader) + "stream" for "gsstream", not "gstream". I have a slight preference for "gsstream" to prevent confusion if we were ever to use "stream" in any other context.

[bogner]

Makes sense to me. Updated the heading to spell out geometry shader and removed the open question.

[tex3d]

I think it's a good start (if I do say so myself ;). Should we merge this then file issues for open questions, and update it as we resolve these?

[inbelic]

This and pos for position above seem to be the only places we use abbreviations of the dxil op name, maybe better to write it all out everywhere?

[bogner]

I think these two abbreviations are both defensible:

• In the "pos" case we're abbreviating from "Texture2DMSGetSamplePosition" to "texturesamplepos". I'm fine with calling this "texturesampleposition" rather than "pos", but it still wouldn't match and I think saying "texture" rather than "texture2dms" is better here.
• "cmpxchg" is an extremely common abbreviation for "compare and exchange" and easy to parse at a glance, whereas "compareexchange" is arguably harder to read.

I don't feel super strongly here, but I have a weak preference for keeping these as is.

[inbelic]

Any reason to keep it as-is is good enough for me

[llvm-beanz]

cc @s-perron & @Keenuts, since we do rely on some of the DX and SPV intrinsics sharing name suffixes.

[Keenuts]

Fine with this!