tree ebd30077b1653e03543662c2c6986a681c2eea72
parent a13c7fd3b34c1deb6592a75e79df9fe44dbf4d88
author Elliott Hughes <enh@google.com> 1397588645 -0700
committer Elliott Hughes <enh@google.com> 1397588645 -0700

Add iswblank for libcxx.

We have similar degenerate implementations for all the other isw* functions,
so it's weird to exclude just one.

Change-Id: I659b97930e68598826c4882bb59f4146870fb6a0