Template instantiation for static data members that are defined out-of-line.

Template instantiation for static data members that are defined out-of-line.

Note that this also fixes a bug that affects non-template code, where we
were not treating out-of-line static data members are "file-scope" variables,
and therefore not checking their initializers.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@77002 91177308-0d34-0410-b5e6-96231b3b80d8