Revert "libc++: Perform configuration checks with -nodefaultlibs"

This reverts SVN r279584 which broke the buildbots.  Will re-apply once the
issue has been root-caused and fixed.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@279596 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed