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/fortify_filecheck_diagnostics_test.cpp b/tests/fortify_filecheck_diagnostics_test.cpp
index a69b967..e79a9a6 100644
--- a/tests/fortify_filecheck_diagnostics_test.cpp
+++ b/tests/fortify_filecheck_diagnostics_test.cpp
@@ -291,7 +291,10 @@
   char from[4] = {0};
   // NOLINTNEXTLINE(whitespace/line_length)
   // CLANG: 'memset' will set 0 bytes; maybe the arguments got flipped?
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wmemset-transposed-args"
   memset(from, sizeof(from), 0);
+#pragma clang diagnostic pop
 }
 
 void test_sendto() {