1.0.32.2: minor portability fix

1.0.32.2: minor portability fix

Clozure CL issues full warnings at compile time if individual clauses in
typecases are shadowed by others; this makes writing portable
warning-free typecases for character types a little bit tricky.  In the
case of the FORMAT directive finders, though, the workaround is
straightforward because the whole of the CHARACTER branch in the
typecases can be removed.

While we're at it, fix the theoretical portability bug that we were
calling the host's CHAR-CODE on BASE-CHARs to fill data structures later
to be accessed using the target's CHAR-CODE.  (Theoretical because all
implementations at present agree on CHAR-CODE for BASE-CHARs).

(This commit does not suffice to allow Clozure CL to build SBCL)

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CVS: Modified Files:
CVS: 	NEWS version.lisp-expr src/code/late-format.lisp
CVS: 	src/code/target-format.lisp
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