Build everything as C++ (#1176)

include/asm/util.hpp

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: MIT */
+
+#ifndef RGBDS_UTIL_H
+#define RGBDS_UTIL_H
+
+#include <stdint.h>
+
+char const *printChar(int c);
+
+/*
+ * @return The number of bytes read, or 0 if invalid data was found
+ */
+size_t readUTF8Char(uint8_t *dest, char const *src);
+
+#endif // RGBDS_UTIL_H