patch 8.2.1133: Vim9: return type of add() is not specific enough

Problem:    Vim9: return type of add() is not specific enough.
Solution:   Return the type of the first argument. (closes #6395)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 2cdf186..c3eaef2 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -441,7 +441,7 @@
 {
     {"abs",		1, 1, FEARG_1,	  ret_any,	FLOAT_FUNC(f_abs)},
     {"acos",		1, 1, FEARG_1,	  ret_float,	FLOAT_FUNC(f_acos)},
-    {"add",		2, 2, FEARG_1,	  ret_any,	f_add},
+    {"add",		2, 2, FEARG_1,	  ret_first_arg, f_add},
     {"and",		2, 2, FEARG_1,	  ret_number,	f_and},
     {"append",		2, 2, FEARG_LAST, ret_number,	f_append},
     {"appendbufline",	3, 3, FEARG_LAST, ret_number,	f_appendbufline},
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index e8d712f..cc938a5 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -602,6 +602,12 @@
     res += n
   endfor
   assert_equal(3, res)
+
+  res = 0
+  for n in add([1, 2], 3)
+    res += n
+  endfor
+  assert_equal(6, res)
 enddef
 
 def Test_func_type_part()
diff --git a/src/version.c b/src/version.c
index ed3f34a..6a22951 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1133,
+/**/
     1132,
 /**/
     1131,