Make test independent of string table entry ordering

The program generated by virtual-function removal depends on where 'B', 'C',
'D', 'E' appear in the string table as there are multiple semantically
equivalent resolutions of virtual functions. The test should pass either way.

Author: tautschnig

regression/cbmc-java/virtual7/test.desc

@@ -3,6 +3,6 @@ test.class
 --show-goto-functions --function test.main
 ^EXIT=0$
 ^SIGNAL=0$
-IF.*"java::C".*THEN GOTO
-IF.*"java::D".*THEN GOTO
+IF.*"java::(B|C)".*THEN GOTO
+IF.*"java::(D|E)".*THEN GOTO
 IF.*"java::A".*THEN GOTO