Added rmdir to stdlib

Author: oholiab

pixie/stdlib.pxi

@@ -18,6 +18,7 @@
 (def fopen (ffi-fn libc "fopen" [CCharP CCharP] CVoidP))
 (def fread (ffi-fn libc "fread" [CVoidP CInt CInt CVoidP] CInt))
 (def mkdtemp (ffi-fn libc "mkdtemp" [CCharP] CCharP))
+(def rmdir (ffi-fn libc "rmdir" [CCharP] CCharP))
 
 (def libm (ffi-library (str "libm." pixie.platform/so-ext)))
 (def atan2 (ffi-fn libm "atan2" [CDouble CDouble] CDouble))