Define [U]LLONG_{MIN,MAX} for C++11, add tests.

Add tests for limits.h, not just [U]LLONG_{MIN,MAX}.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193506 91177308-0d34-0410-b5e6-96231b3b80d8
Fix typo in test's REQUIRES line

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193507 91177308-0d34-0410-b5e6-96231b3b80d8