+;;; FIXME: It'd probably make sense to use a MACROLET to share the
+;;; guts of VECTOR-PUSH between VECTOR-PUSH-EXTEND. Such a macro
+;;; should probably be based on the VECTOR-PUSH-EXTEND code (which is
+;;; new ca. sbcl-0.7.0) rather than the VECTOR-PUSH code (which dates
+;;; back to CMU CL).