Rewrite <fenv.h> for ARM.

The old code was one big no-op.

Bug: http://code.google.com/p/android/issues/detail?id=38196
Change-Id: I201a6ffa477385b2629f45e8c948bdfbd47b5bf1
diff --git a/tests/Android.mk b/tests/Android.mk
index 9d5cd36..66d023f 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -26,6 +26,7 @@
 
 test_src_files = \
     dirent_test.cpp \
+    fenv_test.cpp \
     getcwd_test.cpp \
     libgen_test.cpp \
     pthread_test.cpp \