116c819cc2
After discussing implementing more tests for this with @danalbert & @mclow, I realized this change is not correct. The C++ standard requires do_is() to behave as if it were a loop that checked is(). Furthermore, it requires is() to check "The first form returns the result of the expression (M & m) != 0; i.e., true if the character has the characteristics specified"... which the reverted patch definitely does not conform to. Even further, furthermore, this requires that ctype's mask be an actual bitmask, unlike what android and newlib provide for _ctype_. Fixing the original bug that instigated this patch remains TBD. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@216508 91177308-0d34-0410-b5e6-96231b3b80d8