allow --exec-prefix and arbitrary --with / --enable
a note on cross-compiling
allow strong overrides for all relevant config.mk variables
should be CC -dumpmachine with fallback to cc
buildroot gcc does not like // comments in arm assembly
libc: add raise()
rearrange libs to let libgcc link against libc.a
allow setting ASFLAGS
use monotonic clock for waitneeded
arm: 5th arg for ppoll()
arm: reboot() magic constants