[PCH] In ASTReader::FinishedDeserializing fully load the interesting decls,

including deserializing their bodies, so that any other declarations that
get referenced in the body will be fully deserialized by the time we pass them to the consumer.

Could not reduce to a test case unfortunately. rdar://10587158.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146817 91177308-0d34-0410-b5e6-96231b3b80d8