Disable popcnt in cross-builds, as we can't run programs to check.
Note that using `configure --disable-popcnt` is broken.

--- a/configure	2021-11-21 20:00:41.599629153 -0300
+++ b/configure	2021-11-21 20:00:45.891579837 -0300
@@ -5766,10 +5766,10 @@
 printf %s "checking if popcnt instruction is available and requested... " >&6; }
 if test "$cross_compiling" = yes
 then :
-  { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
-printf "%s\n" "$as_me: error: in \`$ac_pwd':" >&2;}
-as_fn_error $? "cannot run test program while cross compiling
-See \`config.log' for more details" "$LINENO" 5; }
+allow_popcnt=0  # { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+# printf "%s\n" "$as_me: error: in \`$ac_pwd':" >&2;}
+# as_fn_error $? "cannot run test program while cross compiling
+# See \`config.log' for more details" "$LINENO" 5; }
 else $as_nop
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
