[js] box_n/unbox_n, serializing the P6num repr

src/vm/js/QAST/Compiler.nqp

@@ -1222,6 +1222,9 @@ class QAST::OperationsJS {
     add_simple_op('box_i', $T_OBJ, [$T_INT, $T_OBJ]);
     add_simple_op('unbox_i', $T_INT, [$T_OBJ]);
 
+    add_simple_op('box_n', $T_OBJ, [$T_NUM, $T_OBJ]);
+    add_simple_op('unbox_n', $T_NUM, [$T_OBJ]);
+
     add_simple_op('iseq_I', $T_INT, [$T_OBJ, $T_OBJ]);
 
     # bigint arithmetic operators operators

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

@@ -416,3 +416,14 @@ op.iscont = function(cont) {
 op.decont = function(ctx, cont) {
     return cont.$$decont ? cont.$$decont(ctx) : cont;
 };
+
+op.box_n = function(n, type) {
+  var repr = type._STable.REPR;
+  var obj = repr.allocate(type._STable);
+  obj.$$set_num(n);
+  return obj;
+};
+
+op.unbox_n = function(obj) {
+    return obj.$$get_num();
+};

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

@@ -386,9 +386,31 @@ module.exports.P6int = P6int;
 function P6num() {
 }
 
-P6num.prototype.create_obj_constructor = basic_constructor;
+P6num.name = 'P6int';
+P6num.prototype.allocate = basic_allocate;
+P6num.prototype.basic_constructor = basic_constructor;
+P6num.prototype.create_obj_constructor = function(STable) {
+  var c = this.basic_constructor(STable);
+
+  STable.obj_constructor = c; // HACK it's set again later, we set it for addInternalMethod
+
+  STable.addInternalMethod('$$set_num', function(value) {
+    this.value = value;
+  });
+  STable.addInternalMethod('$$get_num', function() {
+    return this.value;
+  });
+  return c;
+};
+
+P6num.prototype.serialize = function(data, object) {
+  data.double(object.value);
+};
+
+P6num.prototype.deserialize_finish = function(object, data) {
+  object.value = data.double();
+};
 
-P6num.name = 'P6num';
 module.exports.P6num = P6num;
 
 function P6str() {