feature/featuretags, ipn/conffile: make HuJSON support in config files optional

Saves 33 KB.

Updates #12614

Change-Id: Ie701c230e0765281f409f29ed263910b9be9cc77
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

feature/buildfeatures/feature_hujsonconf_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_hujsonconf
+
+package buildfeatures
+
+// HasHuJSONConf is whether the binary was built with support for modular feature "HuJSON config file support".
+// Specifically, it's whether the binary was NOT built with the "ts_omit_hujsonconf" build tag.
+// It's a const so it can be used for dead code elimination.
+const HasHuJSONConf = false

feature/buildfeatures/feature_hujsonconf_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_hujsonconf
+
+package buildfeatures
+
+// HasHuJSONConf is whether the binary was built with support for modular feature "HuJSON config file support".
+// Specifically, it's whether the binary was NOT built with the "ts_omit_hujsonconf" build tag.
+// It's a const so it can be used for dead code elimination.
+const HasHuJSONConf = true