gopls/internal/regtest: handle flake in TestCRLF

Make the test a little more stable by making sure diagnostics complete
before organizing imports in these tests.

Change-Id: Id23341569207878554902887498632d6f1ce56cf
Reviewed-on: https://go-review.googlesource.com/c/tools/+/271628
Trust: Rebecca Stambler <rstambler@golang.org>
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>

gopls/internal/regtest/formatting_test.go

@@ -4,6 +4,7 @@ import (
 	"strings"
 	"testing"
 
+	"golang.org/x/tools/internal/lsp"
 	"golang.org/x/tools/internal/lsp/tests"
 )
 
@@ -174,6 +175,7 @@ func Hi() {
 `
 		crlf := strings.ReplaceAll(want, "\n", "\r\n")
 		env.CreateBuffer("main.go", crlf)
+		env.Await(CompletedWork(lsp.DiagnosticWorkTitle(lsp.FromDidOpen), 1))
 		env.SaveBuffer("main.go")
 		got := env.Editor.BufferText("main.go")
 		if want != got {
@@ -212,6 +214,7 @@ func main() {
 `
 		crlf := strings.ReplaceAll(want, "\n", "\r\n")
 		env.CreateBuffer("main.go", crlf)
+		env.Await(CompletedWork(lsp.DiagnosticWorkTitle(lsp.FromDidOpen), 1))
 		env.OrganizeImports("main.go")
 		got := env.Editor.BufferText("main.go")
 		got = strings.ReplaceAll(got, "\r\n", "\n") // convert everything to LF for simplicity