Have stdio.h mingw workarounds too

Signed-off-by: falkTX <falktx@falktx.com>

include/mingw-compat/cstdio

@@ -50,9 +50,6 @@ namespace std {
 }
 */
 
-// extra, there might be warnings for GCC format attribute, ignore those
-#pragma GCC diagnostic ignored "-Wformat"
-
 #else // STDIO_OVERRIDE
 
 // if STDIO_OVERRIDE is not defined, we have nothing to do

include/mingw-compat/stdio.h

@@ -0,0 +1,40 @@
+/*
+ * DISTRHO Cardinal Plugin
+ * Copyright (C) 2021 Filipe Coelho <falktx@falktx.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 3 of
+ * the License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * For a full copy of the GNU General Public License see the LICENSE file.
+ */
+
+#pragma once
+
+/* On mingw stdio functions like printf are not inline, and thus get defined every time they are used.
+ * We go through a few steps to ensure unique symbol names.
+ */
+#ifdef STDIO_OVERRIDE
+
+// helper macros
+# define STDIO_OVERRIDE_HELPER(NS, SEP, FN) NS ## SEP ## FN
+# define STDIO_OVERRIDE_MACRO(NS, FN) STDIO_OVERRIDE_HELPER(NS, _, FN)
+
+// step 1: prefix the needed stdio functions
+# define printf STDIO_OVERRIDE_MACRO(STDIO_OVERRIDE, printf)
+
+// step 2: inlude <stdio.h> which will use our prefixed names
+# include <stdio.h>
+
+#else // STDIO_OVERRIDE
+
+// if STDIO_OVERRIDE is not defined, we have nothing to do
+# include_next <cstdio>
+
+#endif // STDIO_OVERRIDE