Add Object.same(_,_) to access built-in equality even for classes that may override ==.

Had to add a new metaclass for Object since it now has its own static method so we
can't just use Class as its metaclass. (We don't want *every* class to have a same(_,_)
static method.)

test/core/class/name.wren

@@ -5,5 +5,9 @@ IO.print(Foo.type.name) // expect: Foo metaclass
 
 // Make sure the built-in classes have proper names too.
 IO.print(Object.name) // expect: Object
-IO.print(Class.name) // expect: Class
 IO.print(Bool.name) // expect: Bool
+IO.print(Class.name) // expect: Class
+
+// And metaclass names.
+IO.print(Object.type.name) // expect: Object metaclass
+IO.print(Bool.type.name) // expect: Bool metaclass

test/core/class/type.wren

@@ -3,7 +3,7 @@ class Foo {}
 // A class is a class.
 IO.print(Foo is Class) // expect: true
 
-// It's metatype is also a class.
+// Its metatype is also a class.
 IO.print(Foo.type is Class) // expect: true
 
 // The metatype's metatype is Class.

test/core/object/same.wren

@@ -0,0 +1,40 @@
+// Value types compare by value.
+IO.print(Object.same(true, true)) // expect: true
+IO.print(Object.same(true, false)) // expect: false
+
+IO.print(Object.same(null, null)) // expect: true
+
+IO.print(Object.same(1 + 2, 2 + 1)) // expect: true
+IO.print(Object.same(1 + 2, 2 + 2)) // expect: false
+
+IO.print(Object.same(1..2, 1..2)) // expect: true
+IO.print(Object.same(1..2, 1..3)) // expect: false
+
+IO.print(Object.same("ab", "a" + "b")) // expect: true
+IO.print(Object.same("ab", "a" + "c")) // expect: false
+
+// Different types are never the same.
+IO.print(Object.same(null, false)) // expect: false
+IO.print(Object.same(true, 2)) // expect: false
+IO.print(Object.same(1..2, 2)) // expect: false
+IO.print(Object.same("1", 1)) // expect: false
+
+// Classes compare by identity.
+IO.print(Object.same(Bool, Num)) // expect: false
+IO.print(Object.same(Bool, Bool)) // expect: true
+
+// Other types compare by identity.
+class Foo {}
+
+var foo = new Foo
+IO.print(Object.same(foo, foo)) // expect: true
+IO.print(Object.same(foo, new Foo)) // expect: false
+
+// Ignores == operators.
+class Bar {
+  ==(other) { true }
+}
+
+var bar = new Bar
+IO.print(Object.same(bar, bar)) // expect: true
+IO.print(Object.same(bar, new Bar)) // expect: false

test/core/object/type.wren

@@ -0,0 +1,13 @@
+class Foo {}
+
+// Object's class is a class.
+IO.print(Object is Class) // expect: true
+
+// Its metatype is also a class.
+IO.print(Object.type is Class) // expect: true
+
+// The metatype's metatype is Class.
+IO.print(Object.type.type == Class) // expect: true
+
+// Object has a distinct metaclass.
+IO.print(Object.type.name) // expect: Object metaclass