cparse_template_expand() incorrectly appended template parameters to all
destructor nodes it encountered during the tree traversal, including the
dtors of any nested classes.
This resulted in WARN_LANG_ILLEGAL_DESTRUCTOR warnings from
Language::destructorDeclaration() later and possibly other problems due
to not actually wrapping these dtors.
Fix this by explicitly checking if the dtor is a child or, to account
for %extend, a grandchild of the template node itself before appending
template parameters to it.
This commit is best viewed with "-w" (ignore whitespace changes) option
as it indents, without changing, a block of code.
4af2e95010