patch 8.2.3716: Vim9: range without a command is not compiled

Problem:    Vim9: range without a command is not compiled.
Solution:   Add the ISN_EXECRANGE byte code.
diff --git a/src/vim9.h b/src/vim9.h
index 88c0469..c82ba81 100644
--- a/src/vim9.h
+++ b/src/vim9.h
@@ -15,6 +15,7 @@
     ISN_EXEC,	    // execute Ex command line isn_arg.string
     ISN_EXECCONCAT, // execute Ex command from isn_arg.number items on stack
     ISN_EXEC_SPLIT, // execute Ex command from isn_arg.string split at NL
+    ISN_EXECRANGE,  // execute EX command that is only a range
     ISN_LEGACY_EVAL, // evaluate expression isn_arg.string with legacy syntax.
     ISN_ECHO,	    // :echo with isn_arg.echo.echo_count items on top of stack
     ISN_EXECUTE,    // :execute with isn_arg.number items on top of stack