iOS, do not cross-compile for simulator

When compiling for the simulator, we should not
cross compile, since it is only using another sdk.

setting cross-compile when the architecture is the same
causes problems with several third party libs.

The unsolved problem is how to build cmdline tools.

Change-Id: Ida0b31bb12f6eadca413eb6e1874553adb8be6cd

configure.ac

@@ -3075,7 +3075,7 @@ if test "$_os" = "WINNT"; then
         BITNESS_OVERRIDE=64
     fi
 fi
-if test "$_os" = "iOS"; then
+if test "$_os" = "iOS" -a "$host_cpu" = "arm64"; then
     cross_compiling="yes"
 fi