[Bug target/79845] New: rs6000: make code in rd6000.c more i18n-friendly

["roland.illig at gmx dot de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79845

            Bug ID: 79845
           Summary: rs6000: make code in rd6000.c more i18n-friendly
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: roland.illig at gmx dot de
  Target Milestone: ---

from rs6000.c:

    error ("Builtin function %s requires the -mhard-dfp option", name);

There are several variants of the above line. Currently one human translator
for each of the human languages has to translate all these variants one by one.
It would be much easier if the C code looked like this:

    error ("Builtin function %s requires the %s option", name, "-mhard-dfp");

Not only does this reduce the work for translators, it also leads to fewer
possibilities for typos in the translations.