[CRT] Add round and roundf and add it to msvcrtex to make clang v14 happy

sdk/lib/crt/math/roundf.c

@@ -0,0 +1,16 @@
+/*
+ * COPYRIGHT:       BSD - See COPYING.ARM in the top level directory
+ * PROJECT:         ReactOS CRT library
+ * PURPOSE:         Portable implementation of roundf
+ * PROGRAMMER:      Timo Kreuzer (timo.kreuzer@reactos.org)
+ */
+
+#include <math.h>
+
+float roundf(float arg)
+{
+    if (arg < 0.0)
+        return ceilf(arg - 0.5);
+    else
+        return floorf(arg + 0.5);
+}