Ignore a warning in the tests.

I don't know when, but the libc++ tests have regressed a lot. This
cleans up some of the issues.

Test: ./run_tests.py
Bug: None
Change-Id: Ic0ef789428e131b61121c49e294545a701f963bb

buildcmds/Android.mk

@@ -32,6 +32,7 @@ LOCAL_CPPFLAGS := \
     -w \
     -Wno-error=non-virtual-dtor \
     -Wno-reserved-user-defined-literal \
+    -Wno-unused-local-typedef \
 
 # Optimization is causing relocation for nothrow new to be thrown away.
 # http://llvm.org/bugs/show_bug.cgi?id=21421