Update to syn-2 am: 559b5f3107 am: fd2dcef001 am: fe0607416e am: 8ebd4e87c0 am: d11887ffec am: f559f9cf65

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/num-derive/+/2520538

Change-Id: Id7684883cc743d4ece0ad99e5acfb04fe963a2dd
Signed-off-by: Automerger Merge Worker <[email protected]>