dev-php/phpunit: stabilize PHPUnit on all arches.

dev-php/phpunit: stabilize PHPUnit on all arches.

The latest (and only, as of right now) version of PHPUnit in the tree
has been stabilized on amd64 and x86 in bug 635356 to fix
CVE-2017-9841. However, that new version now comes with a bunch of
pure-PHP dependencies, all of which were unstable for most
arches. That left a significant number of packages in permanent ~arch,
as punishment for having a test suite. Since PHPUnit and its
dependencies are all pure-PHP, I'm taking this opportunity to
stabilize them all under the ALLARCHES umbrella.

The following packages are affected:

  * dev-php/File_Iterator
  * dev-php/PHP_CodeCoverage
  * dev-php/PHP_Timer
  * dev-php/PHP_TokenStream
  * dev-php/Text_Template
  * dev-php/doctrine-instantiator
  * dev-php/fedora-autoloader
  * dev-php/myclabs-deepcopy
  * dev-php/phpdocumentor-reflection-common
  * dev-php/phpdocumentor-reflection-docblock
  * dev-php/phpdocumentor-type-resolver
  * dev-php/phpspec-prophecy
  * dev-php/phpunit-mock-objects
  * dev-php/phpunit
  * dev-php/sebastian-code-unit-reverse-lookup
  * dev-php/sebastian-comparator
  * dev-php/sebastian-diff
  * dev-php/sebastian-environment
  * dev-php/sebastian-exporter
  * dev-php/sebastian-global-state
  * dev-php/sebastian-object-enumerator
  * dev-php/sebastian-recursion-context
  * dev-php/sebastian-resource-operations
  * dev-php/sebastian-version
  * dev-php/symfony-yaml
  * dev-php/webmozart-assert

These were all done in a single commit (against the usual better
judgment) because many of the affected packages have PHPUnit test
suites that create circular dependencies, and that would involve
breaking the tree between commits if they had been made individually.

Bug: https://bugs.gentoo.org/635356