Revert "Don't require gstat on OSX"

This reverts commit 36eb53a3ee4db42969aee871dee2da0318ed44bb.

Breaks building on koush's recovery server

Conflicts:
	arch/arm/boot/compressed/Makefile

Change-Id: I1fee3b3793a3a0d3dd7c44fd8aecbf966d533e27