Add support for BIONIC C library (Android). Patch from Dan Albert

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@212724 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__config b/include/__config
index 981cc9f..687f5c1 100644
--- a/include/__config
+++ b/include/__config
@@ -317,6 +317,8 @@
 #if defined(__FreeBSD__)
 #define _LIBCPP_HAS_QUICK_EXIT
 #define _LIBCPP_HAS_C11_FEATURES
+#elif defined(__ANDROID__)
+#define _LIBCPP_HAS_QUICK_EXIT
 #elif defined(__linux__)
 #include <features.h>
 #if __GLIBC_PREREQ(2, 15)