[js] Basic nqp::getlexrel working only on nqp::curlexpad().

Might need to make it work for outer variables, etc. latter on.

Author: pmurias

src/vm/js/QAST/Compiler.nqp

@@ -1455,6 +1455,7 @@ class QAST::OperationsJS {
     }
 
     add_simple_op('getlexdyn', $T_OBJ, [$T_STR], sub ($name) {"{$*CTX}.lookup_dynamic_from_caller($name)"});
+    add_simple_op('getlexrel', $T_OBJ, [$T_OBJ, $T_STR]);
 
     add_simple_op('captureexistsnamed', $T_INT, [$T_OBJ, $T_STR]);
     add_simple_op('capturehasnameds', $T_INT, [$T_OBJ]);

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

@@ -800,3 +800,7 @@ op.srand = function(seed) {
   generator = new XorShift([seed, 0, 0, 0]);
   return seed;
 };
+
+op.getlexrel = function(pad, name) {
+  return pad.lookup(name);
+};

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

@@ -16,4 +16,8 @@ CurLexpad.prototype.$$existskey = function(key) {
   return this.set.hasOwnProperty(key);
 };
 
+CurLexpad.prototype.lookup = function(key) {
+  return this.get.hasOwnProperty(key) ? this.get[key]() : null;
+};
+
 module.exports = CurLexpad;