Force abc to align memory to 8 bytes

Force abc to align memory to 8 bytes

Apparently abc has a memory pool implementation that by default returns
memory that is unaligned. There is a workaround in the abc makefile that
uses uname to look for "arm" specifically and then sets the alignment.
However, ARM is not the only platform that requires proper alignment
(e.g. emscripten does too). For now, pessimistically force the alignment
for 8 bytes all the time (somehow 4 wasn't enough for fixing emscripten
despite being approximately a 32-bit platform).