x/tools/gopls: Definition bug reported by telemetry [kkvfqw]

[adonovan]

This stack vTX2xw was reported by telemetry:

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.Definition:86
golang.org/x/tools/gopls/internal/lsp.(*Server).definition:19
golang.org/x/tools/gopls/internal/lsp.(*Server).Definition:1
golang.org/x/tools/gopls/internal/lsp/protocol.serverDispatch:192
golang.org/x/tools/gopls/internal/lsp/protocol.ServerHandler.func1:5
golang.org/x/tools/gopls/internal/lsp/lsprpc.handshaker.func1:52
golang.org/x/tools/internal/jsonrpc2.MustReplyHandler.func1:2
golang.org/x/tools/internal/jsonrpc2.AsyncHandler.func1.2:3
runtime.goexit:0

golang.org/x/tools/gopls@v0.14.1 go1.19.1 darwin/amd64 (1)

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

[adonovan]

Dup of #64086.