build scripts: always set encoding to UTF-8 when running tests for consistency

build/scripts/tests.gant

@@ -41,7 +41,6 @@ if (System.getProperty("os.name").toLowerCase().startsWith("mac")) {
   if (vendor != null && vendor.toLowerCase().contains("apple")) {
     args << "-d32"
   }
-  args << "-Dfile.encoding=UTF-8"
 };
 
 args << "-Djna.nosys=true"

build/scripts/utils.gant

@@ -338,6 +338,7 @@ binding.setVariable("commonJvmArgsForTests", {
 
   return [
     "-ea",
+    "-Dfile.encoding=UTF-8",
     "-Dio.netty.leakDetectionLevel=PARANOID",
     "-server",
     "-Xbootclasspath/p:${projectBuilder.moduleOutput(findModule("boot"))}",