XCode 4.4 harmful

[Craig Treleaven]

Hi:

In case it helps others, it appears that XCode 4.4 is the cause of a 
run-time problem with mythtv-core.25.  To recap, for some users, one 
of Myth's programs, mythfrontend, would consistently segfault before 
the main window was drawn (with the crashed thread in libunwind):

https://trac.macports.org/ticket/35934

One of the affected users, James George, put a tremendous amount of 
work into tracking down the issue.  We eventually determined that the 
code would run successfully if built with apple-gcc-4.2.  James has 
determined that code produced with XCode 4.3.3 works OK; XCode 4.4.0+ 
leads to crashes.  Testing done on 10.7.4.

There were no obvious errors reported in the XCode 4.4.0+ builds.

Could someone identify what changed from 4.3.3 to 4.4.0 that might 
account for this?  Bonus points if you can put it in simple terms 
that I can follow!  ;)

Craig