Go: Use Homebrew include paths

Fixes #967

Author: danielledeleo

go/ldflags-darwin.go

@@ -0,0 +1,14 @@
+//go:build darwin
+
+/*
+ * Copyright (C) Danielle De Leo
+ * Copyright (C) NGINX, Inc.
+ */
+
+package unit
+
+/*
+#cgo LDFLAGS: -L/opt/homebrew/lib
+#cgo CFLAGS: -I/opt/homebrew/include
+*/
+import "C"