Use -O2 when building with standard compiler flags
Since we are setting CFLAGS explicitly, we override any Makefile defaults, which will often be -O2.
Picked from https://github.com/chef/omnibus/pull/591
Since we are setting CFLAGS explicitly, we override any Makefile defaults, which will often be -O2.
Picked from https://github.com/chef/omnibus/pull/591