[libcxx] Allow shared_ptr's unique_ptr converting constructor to support array types.

Refs: https://bugs.llvm.org/show_bug.cgi?id=32147

Differential Revision: https://reviews.llvm.org/D80882

GitOrigin-RevId: 097d77d611d1e1b3972be661fdc3caaa4d1824b4
3 files changed