Fix up a few bionic tests for the clang-r339409 update.

Disable -Wmemset-transposed-args to ensure that FORTIFY still works
without it. Also, we can finally enable checking for
FLT_HAS_SUBNORM/DBL_HAS_SUBNORM/LDBL_HAS_SUBNORM now that those are
available in Clang.

Bug: http://b/110779387
Test: build and run bionic unit tests
Change-Id: I4bf19b870c44d981ecbd1089d0ae6a2496be5441
diff --git a/tests/float_test.cpp b/tests/float_test.cpp
index a75214e..3ef4593 100644
--- a/tests/float_test.cpp
+++ b/tests/float_test.cpp
@@ -112,16 +112,13 @@
 #if !defined(FLT_EVAL_METHOD)
 #error FLT_EVAL_METHOD
 #endif
-// TODO: FLT_HAS_SUBNORM currently missing from clang. Negate this test when fixed.
-#if defined(FLT_HAS_SUBNORM)
+#if !defined(FLT_HAS_SUBNORM)
 #error FLT_HAS_SUBNORM
 #endif
-// TODO: DBL_HAS_SUBNORM currently missing from clang. Negate this test when fixed.
-#if defined(DBL_HAS_SUBNORM)
+#if !defined(DBL_HAS_SUBNORM)
 #error DBL_HAS_SUBNORM
 #endif
-// TODO: LDBL_HAS_SUBNORM currently missing from clang. Negate this test when fixed.
-#if defined(LDBL_HAS_SUBNORM)
+#if !defined(LDBL_HAS_SUBNORM)
 #error LDBL_HAS_SUBNORM
 #endif
 }