(bind-place! accessor setter)
  accessor: a sym
  setter: a sym

Defines a new type of place.

The = macro searches a small database of "setter functions" when deciding how to deal with its place argument.

The default setters include:

• access= for access
• global= for global
• macro= for macro
• gc-value= for gc-value

Custom places can be used in several different macros: =, inc!, swap!, and so on.