Fix some issues with non-constant initializers

Sponsored-by: EMC / Isilon Storage Division
Put in the necessary libm dependency in DPADD and ensure this is using c99
Fix a type warning and skip the cbrtl testcases on ARM/MIPS/PPC
Try to unbreak tinderbox on arm, mips, and powerpc
Merge branch 'isilon-atf' into isilon-atf-fix-amp-tinderbox
Revert "Disable build/install of msun tests on non-x86 platforms"

This reverts commit 06f0f02531f099b64f77f48539e08f87e3797bb8.
Unbreak powerpc
Skip lib/libc/tests/ssp on arm/mips as the archs don't support WITH_SSP

Sponsored-by: EMC / Isilon Storage Division