[book] Fixed invalid PIR fragment; .lex never worked with non-PMC types. (Found by Michael Hind.)
[book] Fixed invalid PIR fragment; .lex never worked with non-PMC types.
(Found by Michael Hind.)

git-svn-id: 6e74a02f85675cec270f5d931b0f6998666294a3@43467 d31e2699-5ff4-0310-a27c-f18f2fbe73fe

ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot