internal/lsp/cache: keep going on failed analyzers

A single failed analyzer should not prevent others from reporting their
diagnostics. This is especially relevant as we work on updating
analyzers to support generic code.

Change-Id: If1d958347649a99df92701fc4a4574cb7020596b
Reviewed-on: https://go-review.googlesource.com/c/tools/+/351550
Trust: Robert Findley <[email protected]>
Run-TryBot: Robert Findley <[email protected]>
gopls-CI: kokoro <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Rebecca Stambler <[email protected]>

Author: findleyr

internal/lsp/cache/analysis.go

@@ -46,7 +46,9 @@ func (s *snapshot) Analyze(ctx context.Context, id string, analyzers []*source.A
 	for _, ah := range roots {
 		diagnostics, _, err := ah.analyze(ctx, s)
 		if err != nil {
-			return nil, err
+			// Keep going if a single analyzer failed.
+			event.Error(ctx, fmt.Sprintf("analyzer %q failed", ah.analyzer.Name), err)
+			continue
 		}
 		results = append(results, diagnostics...)
 	}