PR 13722 candidate fix

[Arnaud Charlet]

> There is a PR in bugzilla for this problem, PR 5910 and PR 5911.  This 
> has bitten me also,
> now I do not have an Ada compiler for powerpc-apple-darwin at all.

You are confusing issues.
PR 5910 and 5911 have nothing to do with parallel builds failing.

PR 5910 is a duplicate of 5911
PR 5911 is implemented on the libada-branch, and is simply waiting to be
merged by a makefile/configure person.

Arno