Bug#1025307: yosys mips64el build failure (fix)

[Scott Ashcroft]

Hi,

I agree if you only read the C then the code looks fine, if a bit odd.
However, having looked at the coredump with gdb it seems the compiler
optomises the dereference out and passes back a pointer to the soon to
be invalid stack address rather than the value.
It only crashes with the stack protection on and I initially struggled
to reproduce the issue as I was using the upstream compiler flags.

It isn't even handling endianness conversions as it copies the bytes in
the same order they come in. I think their idea was to support
architectures where you can't access an 32-bit int at an odd address.

I'll try you patch and report back.

Cheers,
Scott