BugFix: Fix structures to be visible at compile time from trivia library

[elderica]

Fix for the following error message when compiling with Clozure CL

; While executing: ALEXANDRIA:SIMPLE-STYLE-WARNING, in process listener(1).
> Error: Symbol ASTBLOCK is unbound in namespace PATTERN
> While executing: PATTERN-EXPAND-1, in process listener(1).
> Type :GO to continue, :POP to abort, :R for a list of available restarts.
> If continued: Skip evaluation of (ros:run '((:eval"(ros:quicklisp)")(:source-registry ".")(:eval "(asdf:compile-system \"caten\" :verbose t)")))
> Type :? for other options.

[hikettei]

LGTM