Add semaphore tests, fix sem_destroy.

Bug: https://code.google.com/p/android/issues/detail?id=76088
Change-Id: I4a0561b23e90312384d40a1c804ca64ee98f4066
diff --git a/libc/Android.mk b/libc/Android.mk
index 0f828ed..489200f 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -53,7 +53,6 @@
     bionic/pututline.c \
     bionic/sched_cpualloc.c \
     bionic/sched_cpucount.c \
-    bionic/semaphore.c \
     bionic/sigblock.c \
     bionic/siginterrupt.c \
     bionic/sigsetmask.c \
@@ -182,6 +181,7 @@
     bionic/scandir.cpp \
     bionic/sched_getaffinity.cpp \
     bionic/sched_getcpu.cpp \
+    bionic/semaphore.cpp \
     bionic/send.cpp \
     bionic/setegid.cpp \
     bionic/__set_errno.cpp \