In commit f96a69f916a "mesa: replace GLenum with GLenum16 in common structures (v4)" it looks like Hints.TextureCompression was missed, it's still listed as an int which leads to 0x11001100 being returned instead of 0x1100 as it reads into the next value.
This diff fixes it for me, but there might be something else that needs to update:
diff --git a/src/mesa/main/get_hash_params.py b/src/mesa/main/get_hash_params.py
index e10282a156..df082af207 100644
@@ -783,7 +783,7 @@ descriptor=[
[ "EDGE_FLAG_ARRAY_COUNT_EXT", "CONST(0), NO_EXTRA" ],
- [ "TEXTURE_COMPRESSION_HINT_ARB", "CONTEXT_INT(Hint.TextureCompression), NO_EXTRA" ],
+ [ "TEXTURE_COMPRESSION_HINT_ARB", "CONTEXT_ENUM16(Hint.TextureCompression), NO_EXTRA" ],
[ "ARRAY_ELEMENT_LOCK_FIRST_EXT", "CONTEXT_INT(Array.LockFirst), NO_EXTRA" ],
The patch looks good to me. I'll push it in a bit.
I don't see any other issues related to Hint.TextureCompression.
Unfortunately, there's no Piglit test that hits this.
Fixed with commit 030821a8737cd8a7be001e40dafc1879f3df7866