This patch addresses the following issues in the test suite:
1. Move "std::bad_array_length" test from std/ to libcxx/ test directory
since the feature is not a part of the standard.
2. Rename "futures.tas" test directory to "futures.task" since that is the
correct stable name.
3. Move tests for "packaged_task<T>::result_type" from std/ to libcxx/
test directory since the typedef is a libc++ extension.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@271430 91177308-0d34-0410-b5e6-96231b3b80d8
