Fix FileTree completion in macro context (#829)

hxd/res/FileTree.hx

@@ -1,4 +1,5 @@
 package hxd.res;
+#if macro
 import haxe.macro.Context;
 import haxe.macro.Expr;
 
@@ -375,3 +376,4 @@ class FileTree {
 	}
 
 }
+#end