configure: Check for new-enough getopt

macOS is shipped with an old non-enhanced version of getopt and it
doesn't support options used by run_tests.sh. Proper version of getopt
is available from homebrew but it has to be added to PATH before invoking
run_tests.sh.  Halt ./configure if enhanced getopt can't be found.
Based on a patch by Roman Bolshakov <r.bolshakov@yadro.com>.

Cc: Cameron Esfahani <dirty@apple.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -167,6 +167,13 @@ EOF
   rm -f lib-test.{o,S}
 fi
 
+# require enhanced getopt
+getopt -T > /dev/null
+if [ $? -ne 4 ]; then
+    echo "Enhanced getopt is not available, add it to your PATH?"
+    exit 1
+fi
+
 # Are we in a separate build tree? If so, link the Makefile
 # and shared stuff so that 'make' and run_tests.sh work.
 if test ! -e Makefile; then

run_tests.sh

@@ -34,6 +34,13 @@ EOF
 RUNTIME_arch_run="./$TEST_DIR/run"
 source scripts/runtime.bash
 
+# require enhanced getopt
+getopt -T > /dev/null
+if [ $? -ne 4 ]; then
+    echo "Enhanced getopt is not available, add it to your PATH?"
+    exit 1
+fi
+
 only_tests=""
 args=`getopt -u -o ag:htj:v -l all,group:,help,tap13,parallel:,verbose -- $*`
 [ $? -ne 0 ] && exit 2;