xeno_math: add __powidf2()

looks like gcc4.8 requires this
taken from: http://opensource.apple.com/source/clang/clang-137/src/projects/compiler-rt/lib/
MIT licensed
Merge pull request #194 from mhaberler/xenomath__powidf2

xeno_math: add __powidf2()
Merge pull request #195 from cdsteinkuehler/hal-gantry

hal : components : Add gantry component
hal : components : Fix EOLs in gantry.comp

Signed-off-by: Charles Steinkuehler <charles@steinkuehler.net>