Sigh, revert r4451, I checked this before I comitted but the reason it worked...

Sigh, revert r4451, I checked this before I comitted but the reason it worked was due to a typo (in this case failure was what i was looking for): to do the const check the values must be initialised otherwise (all/most?) compilers will ignore keywords in a signature check unless you actually try to give it a real value.

Originally committed to SVN as r4452.

aegisub/configure.in

@@ -480,7 +480,11 @@ if test "$agi_cv_with_iconv" = "yes"; then
   AC_AGI_COMPILE([iconv (const)], [iconv_const], [$ICONV_CFLAGS], [$ICONV_LDFLAGS],[
 #include <iconv.h>
 int main(void) {
-  size_t iconv (iconv_t cd, const char** in, size_t *inbytesleft, char** out, size_t *outbytesleft);
+  iconv_t cd = iconv_open("UTF-16", "UTF-8");
+  const char *in = "in";
+  char *out = new char();
+  size_t res, inbytesleft, outbytesleft;
+  res = iconv(cd, &in, &inbytesleft, &out, &outbytesleft);
   return 0;
 } ])