1.0.19.1: DERIVE-TYPE optimizer for %%PRIMITIVE

1.0.19.1: DERIVE-TYPE optimizer for %%PRIMITIVE

 * Fixes #427: vintage TRULY-THE annotated the CALL early enough that
   the IR2 conversion of the %PRIMITIVE got the right primitive types.
   Now that TRULY-THE is a regular cast, an optimizer is needed to
   annotate the call.

 * Refactor FIND-TEMPLATE-RESULTS a bit.

 * Get rid of now-pointless TRULY-THE wrappers around several
   %PRIMITIVE calls.

 * Test-case.