[js] Make nqp::say and nqp::print return their arguments.

Author: pmurias

src/vm/js/Operations.nqp

@@ -379,8 +379,8 @@ class QAST::OperationsJS {
 
     add_simple_op('getcomp', $T_OBJ, [$T_STR], :sideffects);
 
-    add_simple_op('say', $T_VOID, [$T_STR], :sideffects);
-    add_simple_op('print', $T_VOID, [$T_STR], :sideffects);
+    add_simple_op('say', $T_STR, [$T_STR], :sideffects);
+    add_simple_op('print', $T_STR, [$T_STR], :sideffects);
 
     add_simple_op('getstderr', $T_OBJ, [], :sideffects);
     add_simple_op('getstdout', $T_OBJ, [], :sideffects);

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

@@ -20,6 +20,7 @@ exports.op = op;
 
 op.print = function(arg) {
   process.stdout.write(arg);
+  return arg;
 };
 
 op.say = function(arg) {
@@ -29,6 +30,7 @@ op.say = function(arg) {
   } else {
     console.log(arg);
   }
+  return arg;
 };
 
 function stat(file, code, lstat) {