tree e3a73e2a031f41b76cb1494e0d64106f5ad5a161
parent ada4105ba2f31be65489526f2900045f611e7bfb
author Alon Bar-Lev <alon.barlev@gmail.com> 1424274905 +0200
committer Manuel Pégourié-Gonnard <mpg@elzevir.fr> 1426253665 +0000

build: Makefile: cleanup CFLAGS

CFLAGS are reserved for external interaction via make variable, the
following should work:

$ make CFLAGS="-O3"
$ CFLAGS="-O3" make

1. Move internal flags to LOCAL_CFLAGS
2. Respect external CFLAGS
3. CFLAGS should be last compiler flags.
4. Default CFLAGS is -O optimization, remove OFLAGS.
5. Add WARNING_CFLAGS to control warning setting and enable to remove
   if compiler does not support flags.

Signed-off-by: Alon Bar-Lev <alon.barlev@gmail.com>