Add iOS support

configure.ac

@@ -328,13 +328,23 @@ if test x$TARGET = xX86_WIN64; then
     fi
 fi
 
+
+FFI_EXEC_TRAMPOLINE_TABLE=0
 case "$target" in
+     *arm*-apple-darwin*)
+       FFI_EXEC_TRAMPOLINE_TABLE=1
+       AC_DEFINE(FFI_EXEC_TRAMPOLINE_TABLE, 1,
+                 [Cannot use PROT_EXEC on this target, so, we revert to
+                   alternative means])
+     ;;
      *-apple-darwin10* | *-*-freebsd* | *-*-openbsd* | *-pc-solaris*)
        AC_DEFINE(FFI_MMAP_EXEC_WRIT, 1,
                  [Cannot use malloc on this target, so, we revert to
                    alternative means])
      ;;
 esac
+AM_CONDITIONAL(FFI_EXEC_TRAMPOLINE_TABLE, test x$FFI_EXEC_TRAMPOLINE_TABLE = x1)
+AC_SUBST(FFI_EXEC_TRAMPOLINE_TABLE)
 
 if test x$TARGET = xX86_64; then
     AC_CACHE_CHECK([assembler supports unwind section type],