Skip iconv checks for darwin builds as iconv is only available from fink and we do not want the extra external dependency.

Thanks to Jerry Talkington <jerry@smartasfuck.com> for the patch.
Bug #216908 r=cls sr=darin a=asa

configure

@@ -8971,7 +8971,7 @@ EOF
 fi
 
 case $target_os in
-    os2*|msvc*|mks*|cygwin*|mingw*)
+    os2*|msvc*|mks*|cygwin*|mingw*|darwin*)
         ;;
     *)
     

configure.in

@@ -2270,7 +2270,7 @@ if test "$ac_cv_func_gnu_get_libc_version" = "yes"; then
 fi
 
 case $target_os in
-    os2*|msvc*|mks*|cygwin*|mingw*)
+    os2*|msvc*|mks*|cygwin*|mingw*|darwin*)
         ;;
     *)