The blacklist in the AddressSanitizer pass constructs one big regular expression from
the blacklist entries. If one of these list entries contains something illegal, then
the whole regex silently fails and nothing is blacklisted. Also no error is emitted
for this.

To test this, create a blacklist using:

fun:main
fun:foo??bar
fun:bar

The second line here is invalid (at least it seems to be in the C++ regular expression
library that is used, as it stopped my blacklist from working. Using this blacklist
won't have any effect, e.g. main will be instrumented.

Tested using LLVM/Clang/ASan SVN trunk revision 146212 on Linux.