Start cleaning up libm.

We have two copies of fenv.h for every architecture, one of which
isn't used. We also have unused makefiles and files for architectures
we don't support.

This patch removes all the obviously useless files.

Bug: http://code.google.com/p/android/issues/detail?id=38196
Change-Id: I1919b6621ba513aa24aa947a34815bc51191487c
diff --git a/libm/include/i387/fenv.h b/libm/include/i387/fenv.h
index 4e322b7..c0421c0 100644
--- a/libm/include/i387/fenv.h
+++ b/libm/include/i387/fenv.h
@@ -29,8 +29,7 @@
 #ifndef	_FENV_H_
 #define	_FENV_H_
 
-#include <sys/cdefs.h>
-#include <sys/_types.h>
+#include <sys/types.h>
 
 __BEGIN_DECLS