Fix regressions from Trunk

[LinqLover]

Fixes several regressions caused by test-related changes in the upstream dependencies.

• Restore PluggableWeakKeyDictionary, which has been rejected to the Trunk (7606a8f)
• Robustize sandbox memory against proxies (737cf6e)
• Honor sandbox memory during message lookup (7187bf7)
• Sandbox: Add mirror primitive support to all #at:[put:] primitives, sizes primitives, and primitiveGetImmutability (25f2d8e)
• Kernel test framework: Fix typo in test groups, increase timeout for sandboxes (03f4cd2)
• Bump prevdep for #runCaseWithoutTimeout to SUnit-ct.133 (fa04ed4)