Use ffi_closure_free by default.

The current conditionals reflect historic heritage of FFI. Usage of
ffi_closure_free should be better default nowadays.

Author: voxik

ext/fiddle/closure.c

@@ -13,14 +13,11 @@ typedef struct {
     ffi_type **argv;
 } fiddle_closure;
 
-#if defined(USE_FFI_CLOSURE_ALLOC)
-#elif defined(__OpenBSD__) || defined(__APPLE__) || defined(__linux__)
-# define USE_FFI_CLOSURE_ALLOC 0
-#elif defined(RUBY_LIBFFI_MODVERSION) && RUBY_LIBFFI_MODVERSION < 3000005 && \
-	(defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || defined(_M_AMD64))
-# define USE_FFI_CLOSURE_ALLOC 0
-#else
-# define USE_FFI_CLOSURE_ALLOC 1
+#ifndef USE_FFI_CLOSURE_ALLOC
+# if defined(RUBY_LIBFFI_MODVERSION) && RUBY_LIBFFI_MODVERSION < 3000005
+#  define USE_FFI_CLOSURE_ALLOC 0
+# else
+#  define USE_FFI_CLOSURE_ALLOC 1
 #endif
 
 static void