use stored AdtMetadata table in pointer cast checks

[aneksteind]

Reduces repeated calls to construct_adt_metadata, thereby reducing instances of for e.g. bubbling up hypothetical lifetimes.

On analyze-recover:

$ cat lighttpd-rust-static.out | grep "bubbling" | wc -l
18538929

and with this commit

$ cat lighttpd-rust-static.out | grep "bubbling" | wc -l
150723

Addresses #875 at least in part