cmd/compile/internal/noder: hide TestUnifiedCompare behind -cmp flag

This test is fragile and is starting to impede others' work. This CL
disables it until I have time to either find a solution for the issues
or decide to just delete the test altogether.

Change-Id: Icefabb6d3fbedec5d16536de78be4ca20d63133c
Reviewed-on: https://go-review.googlesource.com/c/go/+/350729
Trust: Matthew Dempsky <[email protected]>
Trust: Dan Scales <[email protected]>
Run-TryBot: Matthew Dempsky <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Dan Scales <[email protected]>

Author: mdempsky

src/cmd/compile/internal/noder/unified_test.go

@@ -16,6 +16,7 @@ import (
 )
 
 var (
+	flagCmp      = flag.Bool("cmp", false, "enable TestUnifiedCompare")
 	flagPkgs     = flag.String("pkgs", "std", "list of packages to compare (ignored in -short mode)")
 	flagAll      = flag.Bool("all", false, "enable testing of all GOOS/GOARCH targets")
 	flagParallel = flag.Bool("parallel", false, "test GOOS/GOARCH targets in parallel")
@@ -37,6 +38,12 @@ var (
 // command's -run flag for subtest matching is recommended for less
 // powerful machines.
 func TestUnifiedCompare(t *testing.T) {
+	// TODO(mdempsky): Either re-enable or delete. Disabled for now to
+	// avoid impeding others' forward progress.
+	if !*flagCmp {
+		t.Skip("skipping TestUnifiedCompare (use -cmp to enable)")
+	}
+
 	targets, err := exec.Command("go", "tool", "dist", "list").Output()
 	if err != nil {
 		t.Fatal(err)