Merge branch 'jk/clang-pedantic' into maint

A few unportable C construct have been spotted by clang compiler
and have been fixed.

* jk/clang-pedantic:
bswap: add NO_UNALIGNED_LOADS define
avoid shifting signed integers 31 bits

diff --cc builtin/receive-pack.c
Simple merge

diff --cc cache.h
Simple merge