patch 8.2.3210: Vim9: searchpair() sixth argument is compiled

Problem:    Vim9: searchpair() sixth argument is compiled. (Yegappan
            Lakshmanan)
Solution:   Only compile the fifth argument.

src/testdir/test_vim9_builtin.vim

@@ -2569,9 +2569,17 @@ def Test_searchpair()
   unlet g:caught
 
   lines =<< trim END
-      echo searchpair("a", "b", "c", "d", "1", "f")
+      echo searchpair("a", "b", "c", "d", "f", 33)
   END
-  CheckDefAndScriptFailure2(lines, 'E1001:', 'E475:')
+  CheckDefAndScriptFailure2(lines, 'E1001: Variable not found: f', 'E475: Invalid argument: d')
+
+  lines =<< trim END
+      def TestPair()
+        echo searchpair("a", "b", "c", "d", "1", "f")
+      enddef
+      defcompile
+  END
+  CheckScriptSuccess(lines)
 
   bwipe!
 enddef

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3210,
 /**/
     3209,
 /**/

src/vim9compile.c

@@ -3315,7 +3315,7 @@ compile_arguments(char_u **arg, cctx_T *cctx, int *argcount, int is_searchpair)
 	    return FAIL;
 	++*argcount;
 
-	if (is_searchpair && *argcount >= 5
+	if (is_searchpair && *argcount == 5
 		&& cctx->ctx_instr.ga_len == instr_count + 1)
 	{
 	    isn_T *isn = ((isn_T *)cctx->ctx_instr.ga_data) + instr_count;