dev-libs/ppl: new revision to fix the build with clang.

dev-libs/ppl: new revision to fix the build with clang.

This new revision includes an upstream patch (from their git
repository) to fix the build with clang by adding some missing
keywords that should have been there all along. Thanks to Olivier
Huber for the report and for tracking down the patch.

When building with clang, the ./configure script spits out scary
warnings about missing the GCC-specific -frounding-math flag. I
wouldn't worry about it, but judge for yourself.

Closes: https://bugs.gentoo.org/717768
Package-Manager: Portage-2.3.89, Repoman-2.3.20
Signed-off-by: Michael Orlitzky <mjo@gentoo.org>