gccgo -fgo-prefix

[Ian Lance Taylor]

I have committed a patch to the gccgo sources which add an option
-fgo-prefix. This can be used to link programs which include two
different packages with the same name (the same issue which Russ
recently addressed in 6g/8g). If you don't use -fgo-prefix, then you
will be fine as long as you don't have different packages with the
same name. For larger programs, use -fgo-prefix when you compile the
package; a good choice for the option is the name of the directory
where the package will be installed, since it would be odd to have two
different packages with the same name in the same directory. E.g.,
-fgo-prefix=mygolibs/subdir1/subdir2.

This change will require you to rebuild all existing packages, as the
format of the export information has changed slightly; sorry.

Ian