[Sass] Support --unix-newlines on Unix.

doc-src/HAML_CHANGELOG.md

@@ -3,6 +3,10 @@
 * Table of contents
 {:toc}
 
+## 3.0.19 (Unreleased)
+
+* Allow the `--unix-newlines` flag to work on Unix, where it's a no-op.
+
 ## 3.0.18
 
 [Tagged on GitHub](http://github.com/nex3/haml/commit/3.0.18).

doc-src/SASS_CHANGELOG.md

@@ -11,6 +11,8 @@
 
 * Properly detect SCSS files when using `sass -c`.
 
+* Allow the `--unix-newlines` flag to work on Unix, where it's a no-op.
+
 ## 3.0.18
 
 [Tagged on GitHub](http://github.com/nex3/haml/commit/3.0.18).

lib/haml/exec.rb

@@ -79,10 +79,8 @@ module Haml
           @options[:trace] = true
         end
 
-        if ::Haml::Util.windows?
-          opts.on('--unix-newlines', 'Use Unix-style newlines in written files.') do
-            @options[:unix_newlines] = true
-          end
+        opts.on('--unix-newlines', 'Use Unix-style newlines in written files.') do
+          @options[:unix_newlines] = true if ::Haml::Util.windows?
         end
 
         opts.on_tail("-?", "-h", "--help", "Show this message") do