Adds functionality specified by uchar.h

mbrtoc32 and c32rtomb get their implementations from mbrtowc and wcrtomb. The
wc functions now simply call the c32 functions.

Bug: 14646575
Change-Id: I49d4b95fed0f9d790260c996c4d0f8bfd1686324
diff --git a/tests/Android.mk b/tests/Android.mk
index db8dd8c..ffd4f2b 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -108,6 +108,7 @@
     sys_vfs_test.cpp \
     system_properties_test.cpp \
     time_test.cpp \
+    uchar_test.cpp \
     unistd_test.cpp \
     wchar_test.cpp \