libc++: integral types trap on PNaCl

    Reviewers: dschuff, danalbert

    Subscribers: jfb, cfe-commits

    Differential Revision: http://reviews.llvm.org/D6411

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@222842 91177308-0d34-0410-b5e6-96231b3b80d8