feature/featuretags: make CLI connection error diagnostics modular

Updates #12614

Change-Id: I09b8944166ee00910b402bcd5725cd7969e2c82c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

feature/buildfeatures/feature_cliconndiag_disabled.go

@@ -0,0 +1,13 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Code generated by gen.go; DO NOT EDIT.
+
+//go:build ts_omit_cliconndiag
+
+package buildfeatures
+
+// HasCLIConnDiag is whether the binary was built with support for modular feature "CLI connection error diagnostics".
+// Specifically, it's whether the binary was NOT built with the "ts_omit_cliconndiag" build tag.
+// It's a const so it can be used for dead code elimination.
+const HasCLIConnDiag = false

feature/buildfeatures/feature_cliconndiag_enabled.go

@@ -0,0 +1,13 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Code generated by gen.go; DO NOT EDIT.
+
+//go:build !ts_omit_cliconndiag
+
+package buildfeatures
+
+// HasCLIConnDiag is whether the binary was built with support for modular feature "CLI connection error diagnostics".
+// Specifically, it's whether the binary was NOT built with the "ts_omit_cliconndiag" build tag.
+// It's a const so it can be used for dead code elimination.
+const HasCLIConnDiag = true