[Bug pch/61250] Random pch failures on x86_64-apple-darwin1(3|4).

[howarth at bromo dot med.uc.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61250

--- Comment #14 from howarth at bromo dot med.uc.edu ---
Testing https://gcc.gnu.org/ml/gcc-patches/2015-03/msg01334.html in case
correction of the overflow tests eliminates this bug.