[Bug middle-end/57859] -ftrapv does not trap on signed overflows for struct fields (32-bit mode)

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57859

--- Comment #1 from Mikael Pettersson <mikpe at it dot uu.se> ---
With -m64: both test cases work with gcc-3.2.3, and fail with every release
from 3.3.6 up to current trunk.

With -m32: the first test case doesn't trap with any release since 3.2.3, the
second test case traps with current trunk and 4.8, but not with any release
from 3.2.3 to 4.7.3.