message: fix: don't specify a class name for namespaced classes
  Fixes
  The code to put a name for the class was actually wrong, since it introduces a
  name when it shouldn't. And in this case, it also introduced the use of a
  keyword as an identifier, which caused a crash.
diff: @@ -751,7 +751,7 @@ describe('classes', () => {
  class A.B
  a: -> 1
  `, `
  - A.B = class B {
  + A.B = class {
  a() { return 1; }
  };
  `);
  @@ -1223,13 +1223,24 @@ describe('classes', () => {
  `, `
  class Outer {
  static initClass() {
  - this.Inner = class Inner {};
  + this.Inner = class {};
  }
  }
  Outer.initClass();
  `);
  });
  + it('handles a class this-assigned to a keyword name', () => {
  + check(`
  + ->
  + class @for
  + `, `
  + (function() {
  + return this.for = class {};
  + });
  + `);
  + });
  +
  it('allows an external constructor for a simple class', () => {
  check(`
  f = -> @x = 3
  