Fix the #define U64 part of STR #2582: don't define it for Mac OS because its value

varies with architecture.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@8501 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

configure.in

@@ -442,12 +442,14 @@ else
         AC_DEFINE(U32,unsigned long)
     fi
 fi
-if test $ac_cv_sizeof_int -eq 8; then
+if test "$uname" != Darwin; then
-    AC_DEFINE(U64,unsigned)
+	if test $ac_cv_sizeof_int -eq 8; then
-else
+		AC_DEFINE(U64,unsigned)
-    if test $ac_cv_sizeof_long -eq 8; then
+	else
-        AC_DEFINE(U64,unsigned long)
+		if test $ac_cv_sizeof_long -eq 8; then
-    fi
+			AC_DEFINE(U64,unsigned long)
+		fi
+	fi
 fi
 
 dnl Does the C++ compiler support the bool type?