[jvm] Source file / line mapping info included in non-debug builds

```haxe
function main () {
trace("Hello stack trace");
throw 666;
}
```

`haxe --jvm out.jar -main Test -cp "$PWD"`

```
Test.hx:2: Hello stack trace
Exception in thread "main" 666
at _Test.Test_Fields_.main(/home/bruno/trash/tmp-Ywu/Test.hx:3)
at _Test.Test_Fields_.main(/home/bruno/trash/tmp-Ywu/Test.hx:1)
```

I'm thinking the Haxe source filename and line mapping info should only be included in the jar when compiled with -debug?