bindings: Support constants in IDL namespace (IDL parser) Makes IDL parser support constants in IDL namespaces. Change-Id: I7c078019ae2b1008d0569f91104d8a3c68c7a280 Bug: 1214607 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3279320 Commit-Queue: Yuki Shiino <[email protected]> Reviewed-by: Raphael Kubo da Costa <[email protected]> Cr-Commit-Position: refs/heads/main@{#941674} NOKEYCHECK=True GitOrigin-RevId: 36a95fa26422b2731903c72d1274af598351dc7e