patch 8.2.3229: Vim9: runtime and compile time type checks are not the same

Problem:    Vim9: runtime and compile time type checks are not the same.
Solution:   Add more runtime type checks for builtin functions. (Yegappan
            Lakshmanan, closes #8646)
diff --git a/src/terminal.c b/src/terminal.c
index 98b4600..d0d791c 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -5284,11 +5284,6 @@
     FILE	*fd2 = NULL;
     char_u	*textline = NULL;
 
-    if (in_vim9script()
-	    && (check_for_string_arg(argvars, 0) == FAIL
-		|| check_for_dict_arg(argvars, 1) == FAIL))
-	return;
-
     // First open the files.  If this fails bail out.
     fname1 = tv_get_string_buf_chk(&argvars[0], buf1);
     if (do_diff)
@@ -5666,6 +5661,11 @@
     void
 f_term_dumpload(typval_T *argvars, typval_T *rettv)
 {
+    if (in_vim9script()
+	    && (check_for_string_arg(argvars, 0) == FAIL
+		|| check_for_dict_arg(argvars, 1) == FAIL))
+	return;
+
     term_load_dump(argvars, rettv, FALSE);
 }
 
@@ -5675,8 +5675,12 @@
     void
 f_term_getaltscreen(typval_T *argvars, typval_T *rettv)
 {
-    buf_T	*buf = term_get_buf(argvars, "term_getaltscreen()");
+    buf_T	*buf;
 
+    if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
+	return;
+
+    buf = term_get_buf(argvars, "term_getaltscreen()");
     if (buf == NULL)
 	return;
     rettv->vval.v_number = buf->b_term->tl_using_altscreen;
@@ -5729,13 +5733,18 @@
     void
 f_term_getcursor(typval_T *argvars, typval_T *rettv)
 {
-    buf_T	*buf = term_get_buf(argvars, "term_getcursor()");
+    buf_T	*buf;
     term_T	*term;
     list_T	*l;
     dict_T	*d;
 
     if (rettv_list_alloc(rettv) == FAIL)
 	return;
+
+    if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
+	return;
+
+    buf = term_get_buf(argvars, "term_getcursor()");
     if (buf == NULL)
 	return;
     term = buf->b_term;
@@ -5762,8 +5771,12 @@
     void
 f_term_getjob(typval_T *argvars, typval_T *rettv)
 {
-    buf_T	*buf = term_get_buf(argvars, "term_getjob()");
+    buf_T	*buf;
 
+    if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
+	return;
+
+    buf = term_get_buf(argvars, "term_getjob()");
     if (buf == NULL)
     {
 	rettv->v_type = VAR_SPECIAL;
@@ -5847,8 +5860,12 @@
     void
 f_term_getscrolled(typval_T *argvars, typval_T *rettv)
 {
-    buf_T	*buf = term_get_buf(argvars, "term_getscrolled()");
+    buf_T	*buf;
 
+    if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
+	return;
+
+    buf = term_get_buf(argvars, "term_getscrolled()");
     if (buf == NULL)
 	return;
     rettv->vval.v_number = buf->b_term->tl_scrollback_scrolled;
@@ -5860,11 +5877,16 @@
     void
 f_term_getsize(typval_T *argvars, typval_T *rettv)
 {
-    buf_T	*buf = term_get_buf(argvars, "term_getsize()");
+    buf_T	*buf;
     list_T	*l;
 
     if (rettv_list_alloc(rettv) == FAIL)
 	return;
+
+    if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
+	return;
+
+    buf = term_get_buf(argvars, "term_getsize()");
     if (buf == NULL)
 	return;
 
@@ -5916,11 +5938,16 @@
     void
 f_term_getstatus(typval_T *argvars, typval_T *rettv)
 {
-    buf_T	*buf = term_get_buf(argvars, "term_getstatus()");
+    buf_T	*buf;
     term_T	*term;
     char_u	val[100];
 
     rettv->v_type = VAR_STRING;
+
+    if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
+	return;
+
+    buf = term_get_buf(argvars, "term_getstatus()");
     if (buf == NULL)
 	return;
     term = buf->b_term;
@@ -5940,9 +5967,14 @@
     void
 f_term_gettitle(typval_T *argvars, typval_T *rettv)
 {
-    buf_T	*buf = term_get_buf(argvars, "term_gettitle()");
+    buf_T	*buf;
 
     rettv->v_type = VAR_STRING;
+
+    if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
+	return;
+
+    buf = term_get_buf(argvars, "term_gettitle()");
     if (buf == NULL)
 	return;
 
@@ -6179,7 +6211,7 @@
     void
 f_term_getansicolors(typval_T *argvars, typval_T *rettv)
 {
-    buf_T	*buf = term_get_buf(argvars, "term_getansicolors()");
+    buf_T	*buf;
     term_T	*term;
     VTermState	*state;
     VTermColor  color;
@@ -6190,6 +6222,10 @@
     if (rettv_list_alloc(rettv) == FAIL)
 	return;
 
+    if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
+	return;
+
+    buf = term_get_buf(argvars, "term_getansicolors()");
     if (buf == NULL)
 	return;
     term = buf->b_term;
@@ -6218,9 +6254,8 @@
     term_T	*term;
 
     if (in_vim9script()
-	    && (check_for_opt_buffer_arg(argvars, 0) == FAIL
-		|| (argvars[0].v_type != VAR_UNKNOWN
-		    && check_for_opt_list_arg(argvars, 1) == FAIL)))
+	    && (check_for_buffer_arg(argvars, 0) == FAIL
+		|| check_for_list_arg(argvars, 1) == FAIL))
 	return;
 
     buf = term_get_buf(argvars, "term_setansicolors()");