x/tools/gopls: nil deref in x/telemetry/internal/counter.(*Counter).add

[adonovan]

#!stacks
"sigpanic" && "golang.org/x/telemetry/internal/counter.(*Counter).add:=274"

Issue created by stacks.

I suspect this is another case of gopls heap corruption, but haven't investigate yet.

This stack wbY-eA was reported by telemetry:

• crash/crash
• runtime.throw:+9
• runtime.sigpanic:+16
• sync/atomic.(*Uint64).CompareAndSwap:=179
• golang.org/x/telemetry/internal/counter.(*Counter).add:=274
• golang.org/x/telemetry/internal/counter.(*Counter).Add:+26
• golang.org/x/telemetry/internal/counter.(*Counter).Inc:+1
• golang.org/x/tools/gopls/internal/server.(*server).Hover.StartLatencyTimer.func3:+13
• golang.org/x/tools/gopls/internal/server.(*server).Hover.func1:+1
• runtime.deferreturn:+10
• golang.org/x/tools/gopls/internal/server.(*server).Hover:+30
• golang.org/x/tools/gopls/internal/protocol.serverDispatch:+335
• golang.org/x/tools/gopls/internal/lsprpc.(*streamServer).ServeStream.ServerHandler.func3:+5
• golang.org/x/tools/gopls/internal/lsprpc.(*streamServer).ServeStream.handshaker.func4:+52
• golang.org/x/tools/gopls/internal/protocol.Handlers.MustReplyHandler.func1:+2
• golang.org/x/tools/gopls/internal/protocol.Handlers.AsyncHandler.func2.2:+3
• runtime.goexit:+0

golang.org/x/tools/gopls@v0.18.1 go1.24.3 linux/amd64 vscode (1)