Get the cached block info of an interior pointer. Returns null if the
interior pointer's block is not cached.
NOTE: The base ptr in this struct can be cleared asynchronously by the GC,
so any use of the returned BlkInfo should copy it and then check the
base ptr of the copy before actually using it.
TODO: Change this function so the caller doesn't have to be aware of this
issue. Either return by value and expect the caller to always check
the base ptr as an indication of whether the struct is valid, or set
the BlkInfo as a side-effect and return a bool to indicate success.
Get the cached block info of an interior pointer. Returns null if the interior pointer's block is not cached.
NOTE: The base ptr in this struct can be cleared asynchronously by the GC, so any use of the returned BlkInfo should copy it and then check the base ptr of the copy before actually using it.
TODO: Change this function so the caller doesn't have to be aware of this issue. Either return by value and expect the caller to always check the base ptr as an indication of whether the struct is valid, or set the BlkInfo as a side-effect and return a bool to indicate success.