[PATCH] Check overflows for R_390_GOT12 relocs

[Martin Schwidefsky]

Hi Jakub,

> compiles/links with -shared -O2 -m{31,64} -fpic without a single
> error, yet the resulting shared binary is of course buggy because
> more than half (way more with -m64) relocs overflowed.
> Any reason why linker does not check this?

The reason to use complain_overflow_dont was that I couldn't get
complain_overflow_bitfield to work with the unsigned 12 bit displacement
on 2.10. The linker started complaining if the displacement was bigger
then 2047. I never found the time to fix this in the common code parts.
If this works with never versions of binutils then this fix is very
welcomed.

blue skies,
   Martin