configure: allow disable of cross compilation containers

Our docker infrastructure isn't quite as multiarch as we would wish so
lets allow the user to disable it if they want. This will allow us to
use still run check-tcg on non-x86 CI setups.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Tested-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/configure b/configure
index 84b413d..e0c66ee 100755
--- a/configure
+++ b/configure
@@ -302,6 +302,7 @@
 libs_qga=""
 debug_info="yes"
 stack_protector=""
+use_containers="yes"
 
 if test -e "$source_path/.git"
 then
@@ -1534,6 +1535,10 @@
   ;;
   --disable-plugins) plugins="no"
   ;;
+  --enable-containers) use_containers="yes"
+  ;;
+  --disable-containers) use_containers="no"
+  ;;
   *)
       echo "ERROR: unknown option $opt"
       echo "Try '$0 --help' for more information"
@@ -1717,6 +1722,7 @@
                            track the maximum stack usage of stacks created by qemu_alloc_stack
   --enable-plugins
                            enable plugins via shared library loading
+  --disable-containers     don't use containers for cross-building
 
 Optional features, enabled with --enable-FEATURE and
 disabled with --disable-FEATURE, default is enabled if available:
@@ -7992,7 +7998,7 @@
 (for i in $cross_cc_vars; do
   export $i
 done
-export target_list source_path
+export target_list source_path use_containers
 $source_path/tests/tcg/configure.sh)
 
 # temporary config to build submodules