Behavior of $ in regular expressions

The following tests from the FOTS:

	fn-matches-41:
	fn:matches( concat( 'Mary', codepoints-to-string(10) ), 'Mary$' )

	fn-matches-42:
	fn:matches( concat( 'Mary', codepoints-to-string(10) ), 'Mary$', 's' )

are listed as returning "false" for the correct answer.  Why?  This doesn't work the way, for example, ICU's regular expressions work; see:

	http://stackoverflow.com/questions/12566811/

- Paul