feat: race build tag flag detector

`RaceEnabled` is populated depending on the provided build tags.

Signed-off-by: Artem Chernyshev <artem.0xD2@gmail.com>

README.md

@@ -4,3 +4,4 @@
 
 `go-debug` is a Sidero-specific library for including debugging facilities for developers in our products when they are compiled with `sidero.debug` build tag.
 They are not included by default.
+Also provides utils for detecting if the code was compiled with `race` build tag.

debug.go

@@ -4,6 +4,7 @@
 
 // Package debug is a Sidero-specific library for including debugging facilities for developers in our products
 // when they are compiled with sidero.debug build tag. They are not included by default.
+// Also provides utils for detecting if the code was compiled with race build tag.
 package debug
 
 import (

race_off.go

@@ -0,0 +1,10 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+// +build !race
+
+package debug
+
+// RaceEnabled is false when compiled without race build tag.
+const RaceEnabled = false

race_on.go

@@ -0,0 +1,10 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+// +build race
+
+package debug
+
+// RaceEnabled is true when compiled with race build tag.
+const RaceEnabled = true