I really need to find a way to automate this, but I can't come up with a regex
that has no false positives while handling tricky cases like custom check
prefixes.
llvm-svn: 162097
If integer overflow causes one of the terms to reach zero, that can
force the entire expression to zero.
Fixes PR12929: cast<Ty>() argument of incompatible type
llvm-svn: 157673