to the Materializer.  Materialization is still done by
the ClangExpressionDeclMap; this will be the next thing
to move.

Also fixed a layout bug that this uncovered.

llvm-svn: 179318

information about each variable that needs to
be materialized for an expression to work.  The
next step is to migrate all materialization code
from ClangExpressionDeclMap to Materializer, and
to use it for variable materialization.

llvm-svn: 179245