PR c++/86485 - -Wmaybe-unused with empty class ?:

PR c++/86485 - -Wmaybe-unused with empty class ?:

	* typeck.c (build_static_cast_1): Use cp_build_addr_expr.

For GCC 9 I fixed this bug with a patch to gimplify_cond_expr, but this
function was also doing the wrong thing.

Using build_address does not push the ADDR_EXPR down into the arms of a
COND_EXPR, which we need for proper handling of conversion of an lvalue ?:
to another reference type.

From-SVN: r270985