The Syntax transformer that re-writes the "%define" internal form.
This is used to implement define, define-private, and define-constant.
Syntax: (%define name code type value).
The name is an identifier (String or
Symbol) or Declaration.
The code is an integer mask,
where 1 means type specified, 2 means a function definition,
4 means private, 8 means constant, and 16 means an early constant.
As a special case, define-procedure is 1+2+8+16=27
The type is the declarated type or null.
The value is the initializing value.