There are three issues with the current redhat-rpm-config package on
ARM systems:

1. The copy of config.guess in redhat-rpm-config always reports
   *-unknown-*-*, even if we are running on a Fedora ARM install,
   and it always reports -gnu even if we are running on an ARM
   system that uses EABI, where the upstream convention (followed
   by upstream binutils, gcc, glibc) is to use -gnueabi.

2. redhat-rpm-config's rpmrc file doesn't have optflags defines for
   any of the more modern arm architecture generations.

3. redhat-rpm-config's macros file unconditionally defines %_gnu as
   -gnu, overriding any previous declaration of that macro in rpm's
   macros file or in the platform's macros file.  On ARM EABI systems,
   we have %{_gnu} defined as -gnueabi in the platform macros files,
   but redhat-rpm-config's macros file sets this back to -gnu.

The attached patch fixes these issues, and produces a redhat-rpm-config
package that works fine on arm.  The first two issues are solved in a
supposedly uncontroversial way, but the solution for the third might be
a bit controversial: since the previous macros files already define
%{_gnu}, I simply deleted the %{_gnu} define from redhat-rpm-config's
macros file.

Comments?