gopls/internal/lsp/cache: suppress panics during analysis

We now have a plausible model for the cause of the analysis
crashes and are disabling this check until we have submitted
a plausible fix.

(Specifically: actionHandle.promise may be a stale promise
for an older package with the same ID, since snapshot.actions
uses the package ID as a key. This causes us to re-use
stale inspectors, whose syntax nodes won't be found in TypesInfo.)

Updates golang/go#54762
Updates golang/go#56035

Change-Id: I1a7cc1b02b8c322692b1a6bee03f6cd858c08ea0
Reviewed-on: https://go-review.googlesource.com/c/tools/+/440179
TryBot-Result: Gopher Robot <[email protected]>
gopls-CI: kokoro <[email protected]>
Run-TryBot: Alan Donovan <[email protected]>
Reviewed-by: Bryan Mills <[email protected]>
Auto-Submit: Alan Donovan <[email protected]>

Author: adonovan

gopls/internal/lsp/cache/analysis.go

@@ -365,7 +365,11 @@ func actionImpl(ctx context.Context, snapshot *snapshot, deps []*actionHandle, a
 			if r := recover(); r != nil {
 				// An Analyzer crashed. This is often merely a symptom
 				// of a problem in package loading.
-				if bug.PanicOnBugs && analyzer.Name != "fact_purity" {
+				// Now that we have a theory of these crashes,
+				// we disable the check to stop flakes from being a nuisance.
+				// TODO(adonovan): re-enable it when plausibly fixed.
+				const strict = false
+				if strict && bug.PanicOnBugs && analyzer.Name != "fact_purity" {
 					// During testing, crash. See issues 54762, 56035.
 					// But ignore analyzers with known crash bugs:
 					// - fact_purity (dominikh/go-tools#1327)