Sema: attribute((annotate)) must have at least one argument

Sema::handleAnnotateAttr expects that some basic validation is done on
the given AttributeList.  However, ProcessAccessDeclAttributeList called
it directly.  Instead, pass the list to ProcessDeclAttribute.

This fixes PR21847.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@224204 91177308-0d34-0410-b5e6-96231b3b80d8