x/tools/gopls: gopls generates errors for code in files that have been deleted

[renthraysk]

What version of Go are you using (go version)?

$ go version

go version go1.13.7 linux/amd64

Does this issue reproduce with the latest release?

Yes

What did you do?

Open a deleted file in VSCode's Source Control tab.
Depending on how much refactoring of the code as under gone, this can generate errors, but completely unhelpful as the code is defunct.

What did you expect to see?

No errors generated from deleted files.

What did you see instead?

Errors generated

[gopherbot]

Thank you for filing a gopls issue! Please take a look at the Troubleshooting guide, and make sure that you have provided all of the relevant information here.

[gopherbot]

Change https://golang.org/cl/218278 mentions this issue: internal/lsp/lsprpc: add test for empty diagnostics in deleted files

[gopherbot]

Change https://golang.org/cl/220079 mentions this issue: internal/lsp: clear diagnostics for deleted files