This change trims the function bodies from the ASTs of files belonging to
dependency packages. In these cases, we do not necessarily need full
file ASTs, so it's not necessary to store the function bodies in memory.
This change will reduce memory usage. However, it will also slow down
the case of a user opening a file in a dependency package, as we will
have to re-typecheck the file to get the full AST. Hopefully, this
increase in latency will not be significant, as we will only need to
re-typecheck a single package (all the dependencies should be cached).
Updates golang/go#30309
Change-Id: I7871ae44499c851d1097087bd9d3567bb27db691
Reviewed-on: https://go-review.googlesource.com/c/tools/+/178719
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
