Fix another strdup

src/SDL.cake

@@ -8,7 +8,7 @@
  (c-preprocessor-define-constant SDL_MAIN_HANDLED 1)
  (c-import "SDL.h" "SDL_syswm.h"))
 
-(c-import "<stdio.h>" &with-decls "<stddef.h>" "<stdbool.h>")
+(c-import "<stdio.h>" "<string.h>" &with-decls "<stddef.h>" "<stdbool.h>")
 
 (register-module-license "SDL" s-sdl-license-string)
 
@@ -155,6 +155,7 @@
     (var device-name (addr (const char)) (SDL_GetAudioDeviceName i is-capture))
     (when device-name
       (fprintf stderr "\t[%d] %s\n" i device-name)
+      (declare-extern-function strdup (str (addr (const char)) &return (addr char)))
       (set (at i (deref device-names-out)) (strdup device-name)))
     (incr i))
   (return num-devices))