This ensures that `=>` and `else` have the same bindings as the ones in `racket/private/cond`; otherwise it would not be possible to use SRFI 61 `cond` from a `#lang racket/base` program/module. Tested under both `#lang racket` and `#lang mzscheme`.
svn: r8786
svn: r1702
svn: r1655