syntax/parse: added syntax/parse/pre

No *residual* dependencies on racket/contract/base (the *disappearing*
macro transformers and compile-time support do use contracts, though).

original commit: 323aff1efb4017e3559bbb7f2cc90d699548e730

collects/macro-debugger/analysis/private/moduledb.rkt

@@ -59,6 +59,7 @@
      scheme/gui/base
      slideshow/base
      string-constants
+     syntax/parse
      wxme)))
 
 (define no-bypass-rxs