Name function arguments in libc headers for Studio.

First batch of headers...

Bug: http://b/64613623
Test: builds
Change-Id: I6bc3ad79daa635456b61d03b1f43f06c433ec596
diff --git a/libc/include/android/dlext.h b/libc/include/android/dlext.h
index ca3bd25..c824544 100644
--- a/libc/include/android/dlext.h
+++ b/libc/include/android/dlext.h
@@ -129,7 +129,7 @@
   struct android_namespace_t* library_namespace;
 } android_dlextinfo;
 
-void* android_dlopen_ext(const char* filename, int flag, const android_dlextinfo* extinfo)
+void* android_dlopen_ext(const char* __filename, int __flags, const android_dlextinfo* __info)
   __INTRODUCED_IN(21);
 
 __END_DECLS