Testing plperl<->plperlu interaction

I was investigating a bug in an 8.4.1 production system and distilled a
test case down to this:

    CREATE OR REPLACE FUNCTION bar() RETURNS integer AS $$
        #die 'BANG!'; # causes server process to exit(2)
        # alternative - causes server process to exit(255)
        spi_exec_query("invalid sql statement");
    $$ language plperl; -- plperl or plperlu
   
    CREATE OR REPLACE FUNCTION foo() RETURNS integer AS $$
        spi_exec_query("SELECT * FROM bar()");
        return 1;
    $$ LANGUAGE plperlu; -- must be opposite to language of bar
   
    SELECT * FROM bar(); -- throws exception normally
    SELECT * FROM foo(); -- causes the server to exit abnormaly

before then rereading the 8.4.2 release notes and seeing that the bug
was already fixed. D'oh!

I see the test suite doesn't have any plperlu tests at all.
Is there any reason for that?

Tim.