previously this supposedly was
#2 0x00007fefe9ef79e8 in ?? () at /usr/lib/dri/i965_dri.so
nowadays the ?? is simply empty. the rating mechanism wasn't properly
handling this. treat an empty function name to mean the same as ?? and
rate the line as MissingFunction/Everything depending on whether
libraryName is also missing.
also update test expectations accordingly (could have actually seen that
discrepancy if one had paid attention to the outcoming rating :S)
CCBUG: 418538