Created an analogous data structure for go.mod files when we parse them
using the golang.org/x/mod package. Gopls can now access the data
within a go.mod file using a parseModHandle and the corresponding
parseModData object. This will help down the road when it is time
to implement the lsp functions for go.mod files.
Updates golang/go#31999
Change-Id: Ibd4d64569bbe3df61b203490b63399d479e7d794
Reviewed-on: https://go-review.googlesource.com/c/tools/+/211303
Run-TryBot: Rohan Challa <rohan@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
