Clean up constructor tests.

test/constructor/named.wren

@@ -0,0 +1,20 @@
+class Foo {
+  this bar { io.write("this bar") }
+  this baz { io.write("this baz") }
+  this bar(arg) { io.write("this bar " + arg) }
+
+  toString { "Foo" }
+}
+
+// Different names.
+Foo.bar // expect: this bar
+Foo.baz // expect: this baz
+
+// Can overload by arity.
+Foo.bar // expect: this bar
+Foo.bar("one") // expect: this bar one
+
+// Returns the new instance.
+var foo = Foo.bar // expect: this bar
+io.write(foo is Foo) // expect: true
+io.write(foo.toString) // expect: Foo

test/constructor/new.wren

@@ -0,0 +1,18 @@
+class Foo {
+  // TODO(bob): Do we want to require an explicit "new" here?
+  this new { io.write("zero") }
+  this new(a) { io.write(a) }
+  this new(a, b) { io.write(a + b) }
+
+  toString { "Foo" }
+}
+
+// Can overload by arity.
+Foo.new // expect: zero
+Foo.new("one") // expect: one
+Foo.new("one", "two") // expect: onetwo
+
+// Returns the new instance.
+var foo = Foo.new // expect: zero
+io.write(foo is Foo) // expect: true
+io.write(foo.toString) // expect: Foo