procedures-with-setters, debitrot `optimize', dedottification

procedures-with-setters, debitrot `optimize', dedottification

* module/system/base/syntax.scm (define-record): Define the accessors as
  procedures-with-setters, not just as getters.

* module/system/il/compile.scm (optimize): This function was bitrotten
  since the addition of source locations in
  cb4cca12e719edfef1740f238d9187c21c8e1e35. Untested attempts to
  de-bitrot it. Dedottify as well.

* module/system/il/ghil.scm:
* module/system/il/glil.scm (unparse):
* module/system/vm/debug.scm (debugger-repl): Ongoing dedottification.