0.9.15.28: less instrumentation

0.9.15.28: less instrumentation

 * Don't instrument inline-expansions of known functions. Fixes at
   least some of the "step-instrumentation confusing the compiler"
   problems.

 * Rename IR1-CONVERT-LAMBDA-FOR-DEFUN to
   IR1-CONVERT-INLINE-EXPANSION, since that is the only way it is
   currently used. Refactor slightly for simplicity, given the way it
   is actually used.

 * Test-case.