refactor: iwyu (#26062)

src/nvim/base64.c

@@ -1,7 +1,9 @@
 #include <assert.h>
 #include <stddef.h>
+#include <stdint.h>
 #include <string.h>
 
+#include "auto/config.h"
 #include "nvim/base64.h"
 #include "nvim/memory.h"
 
@@ -9,6 +11,10 @@
 # include ENDIAN_INCLUDE_FILE
 #endif
 
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "base64.c.generated.h"  // IWYU prgama: export
+#endif
+
 static const char alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 
 // Indices are 1-based because we use 0 to indicate a letter that is not part of the alphabet