Implement printing to stderr.

Author: pmurias

src/vm/js/QAST/Compiler.nqp

@@ -509,6 +509,8 @@ class QAST::OperationsJS {
     add_simple_op('say', $T_VOID, [$T_STR], :sideffects);
     add_simple_op('print', $T_VOID, [$T_STR], :sideffects);
 
+    add_simple_op('getstderr', $T_OBJ, [], :sideffects);
+
     add_simple_op('open', $T_OBJ, [$T_STR, $T_STR], :sideffects);
 
     add_simple_op('tellfh', $T_INT, [$T_OBJ], :sideffects);

src/vm/js/nqp-runtime/io.js

@@ -236,3 +236,13 @@ op.getenvhash = function() {
   }
   return hash;
 };
+
+function Stderr() {
+};
+Stderr.prototype.printfh = function(msg) {
+    process.stderr.write(msg);
+}
+
+op.getstderr = function() {
+    return new Stderr();
+};