gopls/internal/lsp: delete dead code

Delete some gopls code that is no longer used.

Change-Id: Ib211b01b6c2ac8a03700b1e47d32ac69fccd1b83
Reviewed-on: https://go-review.googlesource.com/c/tools/+/435360
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
diff --git a/gopls/internal/lsp/cache/snapshot.go b/gopls/internal/lsp/cache/snapshot.go
index aa088bb..4398142 100644
--- a/gopls/internal/lsp/cache/snapshot.go
+++ b/gopls/internal/lsp/cache/snapshot.go
@@ -31,11 +31,11 @@
 	"golang.org/x/mod/semver"
 	"golang.org/x/sync/errgroup"
 	"golang.org/x/tools/go/packages"
-	"golang.org/x/tools/internal/event"
-	"golang.org/x/tools/internal/gocommand"
-	"golang.org/x/tools/internal/bug"
-	"golang.org/x/tools/internal/event/tag"
 	"golang.org/x/tools/gopls/internal/lsp/source"
+	"golang.org/x/tools/internal/bug"
+	"golang.org/x/tools/internal/event"
+	"golang.org/x/tools/internal/event/tag"
+	"golang.org/x/tools/internal/gocommand"
 	"golang.org/x/tools/internal/memoize"
 	"golang.org/x/tools/internal/packagesinternal"
 	"golang.org/x/tools/internal/persistent"
@@ -1612,15 +1612,6 @@
 	return files
 }
 
-func contains(views []*View, view *View) bool {
-	for _, v := range views {
-		if v == view {
-			return true
-		}
-	}
-	return false
-}
-
 // TODO(golang/go#53756): this function needs to consider more than just the
 // absolute URI, for example:
 //   - the position of /vendor/ with respect to the relevant module root