    Execute shell builtins.
    
    Execute SHELL-BUILTIN with arguments ARGs without performing command
    lookup.  This is useful when you wish to reimplement a shell builtin
    as a shell function, but need to execute the builtin within the function.
    
    Exit Status:
    Returns the exit status of SHELL-BUILTIN, or false if SHELL-BUILTIN is
    not a shell builtin..
