gopls/internal/regtest: exit if small machine

The issues we've experienced with linux-arm appear to simply be due to
memory constraints, which is already tracked in golang/go#32834 and
guarded by testenv.ExitIfSmallMachine. No issues on the larger
linux-arm-aws builder.

Remove our guard in favor of testenv.ExitIfSmallMachine.

Fixes golang/go#43355

Change-Id: Idea84e4fff13e13ab9a7eb3414c6133fff0f1e8e
Reviewed-on: https://go-review.googlesource.com/c/tools/+/291469
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
diff --git a/gopls/internal/regtest/regtest.go b/gopls/internal/regtest/regtest.go
index 7133e8f..7a4fa27 100644
--- a/gopls/internal/regtest/regtest.go
+++ b/gopls/internal/regtest/regtest.go
@@ -83,10 +83,9 @@
 }
 
 // Main sets up and tears down the shared regtest state.
-//
-// TODO(rFindley): This is probably not necessary, and complicates things now
-//                 that we have multiple regtest suites. Consider removing.
 func Main(m *testing.M) {
+	testenv.ExitIfSmallMachine()
+
 	flag.Parse()
 	if os.Getenv("_GOPLS_TEST_BINARY_RUN_AS_GOPLS") == "true" {
 		tool.Main(context.Background(), cmd.New("gopls", "", nil, nil), os.Args[1:])
diff --git a/gopls/internal/regtest/runner.go b/gopls/internal/regtest/runner.go
index 6e2c4d5..a029b9c 100644
--- a/gopls/internal/regtest/runner.go
+++ b/gopls/internal/regtest/runner.go
@@ -299,7 +299,6 @@
 	"openbsd-386-64":          "golang.org/issues/42789",
 	"openbsd-386-68":          "golang.org/issues/42789",
 	"openbsd-amd64-68":        "golang.org/issues/42789",
-	"linux-arm":               "golang.org/issues/43355",
 	"darwin-amd64-10_12":      "",
 	"freebsd-amd64-race":      "",
 	"illumos-amd64":           "",