Reduce duplication of compilation commands

[Paolo Bonzini]

On 08/24/2011 12:06 AM, Joseph S. Myers wrote:
> This patch, relative to a tree with my patch
> <http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01930.html>  applied,
> reduces the number of explicit compilation rules in gcc/ and
> subdirectory makefiles by using CFLAGS-$@ settings when a target needs
> extra compiler options.

That patch is okay too, by the way; DJ's comment about non-g++ flags 
does not apply IMO to CFLAGS-$@ which is used exclusively with -D and -I.

Paolo