The goal of this patch is to make isa-l testsuite pass on s390 with
minimal changes to the library. The one and only reason isa-l does not
work on s390 at the moment is that s390 is big-endian, and isa-l
assumes little-endian at a lot of places.
There are two flavors of this: loading/storing integers from/to
memory, and overlapping structs. Loads/stores are already helpfully
wrapped by unaligned.h header, so replace the functions there with
endianness-aware variants. Solve struct member overlap by reversing
their order on big-endian.
Also, fix a couple of usages of uninitialized memory in the testsuite
(found with MemorySanitizer).
Fixes s390x part of #188.
Change-Id: Iaf14a113bd266900192cc8b44212f8a47a8c7753
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>