Add a bunch of stdlib declarations for SM 6.4 and 6.5 (#1221)

The main thing this adds is the `RayQuery` type with its `TraceRayInline` method for DXR 1.1.

None of these new functions/types/constants have been tested, and many of them are not expected to work at all (e.g., we don't actually have any mesh shader support, so adding them as stage types is just for completeness at the API level).

I would like to write some test cases after this is checked in by looking for existing DXR 1.1 examples. We currently have an issue around default initialization that means we probably can't run any DXR 1.1 shaders right now with just the stdlib changes.

1 files changed, 2 insertions, 0 deletions

diff --git a/slang.h b/slang.h
index ad23b47a3..5e75b6f03 100644
--- a/slang.h
+++ b/slang.h
@@ -652,6 +652,8 @@ extern "C"
         SLANG_STAGE_CLOSEST_HIT,
         SLANG_STAGE_MISS,
         SLANG_STAGE_CALLABLE,
+        SLANG_STAGE_MESH,
+        SLANG_STAGE_AMPLIFICATION,
 
         // alias:
         SLANG_STAGE_PIXEL = SLANG_STAGE_FRAGMENT,