x/tools/gopls: Hover bug reported by telemetry

[adonovan]

This stack Az25zA, 6Mf_zA was reported by telemetry:

parseFull:3 is https://cs.opensource.google/go/x/tools/+/refs/tags/gopls/v0.14.1:gopls/internal/lsp/source/hover.go;l=823
bug.Errorf("internal error: no file for position %d", pos)

gopls/bug
golang.org/x/tools/gopls/internal/bug.report:35
golang.org/x/tools/gopls/internal/bug.Errorf:2
golang.org/x/tools/gopls/internal/lsp/source.parseFull:3
golang.org/x/tools/gopls/internal/lsp/source.hover:100
golang.org/x/tools/gopls/internal/lsp/source.Hover:4
golang.org/x/tools/gopls/internal/lsp.(*Server).hover:18
golang.org/x/tools/gopls/internal/lsp.(*Server).Hover:1
golang.org/x/tools/gopls/internal/lsp/protocol.serverDispatch:300
golang.org/x/tools/gopls/internal/lsp/lsprpc.(*StreamServer).ServeStream.ServerHandler.func3:5
golang.org/x/tools/gopls/internal/lsp/lsprpc.(*StreamServer).ServeStream.handshaker.func4:52
golang.org/x/tools/gopls/internal/lsp/protocol.Handlers.MustReplyHandler.func1:2
golang.org/x/tools/gopls/internal/lsp/protocol.Handlers.AsyncHandler.func2.2:3
runtime.goexit:0

golang.org/x/tools/[email protected] devel windows/amd64 (1)
golang.org/x/tools/[email protected] go1.21.1 darwin/arm64 (1)

Reported using [golang.org/x/tools/gopls/internal/telemetry/cmd/stacks].

[findleyr]

Q: what is the non-empty package with no positions. A: unsafe.

We really should keep a running tally of these.

[gopherbot]

Change https://go.dev/cl/544616 mentions this issue: gopls/internal/lsp/source: fix hover for objects in unsafe