* module/srfi/srfi-35.scm (%make-condition-type): New procedure.
(make-condition-type, make-compound-condition-type): Use it.
* test-suite/tests/srfi-35.test ("condition
types")["struct-vtable-name"]: New test.
* module/srfi/srfi-35.scm: Use `(ice-9 syncase)'.
(define-condition-type, condition): Rewritten using `syntax-rules'.
(compound-condition, condition-instantiation): New helper internal
macros. Thanks to Andy Wingo for his help!