patch 8.2.1475: Vim9: can't use v:true for option flags

Problem:    Vim9: can't use v:true for option flags.
Solution:   Add tv_get_bool_chk(). (closes #6725)
diff --git a/src/channel.c b/src/channel.c
index f20a4d8..3e7ec96 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -4922,7 +4922,7 @@
 	    {
 		if (!(supported & JO_MODE))
 		    break;
-		opt->jo_noblock = tv_get_number(item);
+		opt->jo_noblock = tv_get_bool(item);
 	    }
 	    else if (STRCMP(hi->hi_key, "in_io") == 0
 		    || STRCMP(hi->hi_key, "out_io") == 0
@@ -4949,7 +4949,7 @@
 	    {
 		if (!(supported & JO_MODE))
 		    break;
-		opt->jo_pty = tv_get_number(item);
+		opt->jo_pty = tv_get_bool(item);
 	    }
 	    else if (STRCMP(hi->hi_key, "in_buf") == 0
 		    || STRCMP(hi->hi_key, "out_buf") == 0
@@ -4980,7 +4980,7 @@
 		if (!(supported & JO_OUT_IO))
 		    break;
 		opt->jo_set |= JO_OUT_MODIFIABLE << (part - PART_OUT);
-		opt->jo_modifiable[part] = tv_get_number(item);
+		opt->jo_modifiable[part] = tv_get_bool(item);
 	    }
 	    else if (STRCMP(hi->hi_key, "out_msg") == 0
 		    || STRCMP(hi->hi_key, "err_msg") == 0)
@@ -4990,7 +4990,7 @@
 		if (!(supported & JO_OUT_IO))
 		    break;
 		opt->jo_set2 |= JO2_OUT_MSG << (part - PART_OUT);
-		opt->jo_message[part] = tv_get_number(item);
+		opt->jo_message[part] = tv_get_bool(item);
 	    }
 	    else if (STRCMP(hi->hi_key, "in_top") == 0
 		    || STRCMP(hi->hi_key, "in_bot") == 0)
@@ -5184,7 +5184,7 @@
 		if (!(supported2 & JO2_VERTICAL))
 		    break;
 		opt->jo_set2 |= JO2_VERTICAL;
-		opt->jo_vertical = tv_get_number(item);
+		opt->jo_vertical = tv_get_bool(item);
 	    }
 	    else if (STRCMP(hi->hi_key, "curwin") == 0)
 	    {
@@ -5224,14 +5224,14 @@
 		if (!(supported2 & JO2_HIDDEN))
 		    break;
 		opt->jo_set2 |= JO2_HIDDEN;
-		opt->jo_hidden = tv_get_number(item);
+		opt->jo_hidden = tv_get_bool(item);
 	    }
 	    else if (STRCMP(hi->hi_key, "norestore") == 0)
 	    {
 		if (!(supported2 & JO2_NORESTORE))
 		    break;
 		opt->jo_set2 |= JO2_NORESTORE;
-		opt->jo_term_norestore = tv_get_number(item);
+		opt->jo_term_norestore = tv_get_bool(item);
 	    }
 	    else if (STRCMP(hi->hi_key, "term_kill") == 0)
 	    {
diff --git a/src/proto/typval.pro b/src/proto/typval.pro
index 3bc2f2c..15f9345 100644
--- a/src/proto/typval.pro
+++ b/src/proto/typval.pro
@@ -6,6 +6,7 @@
 void init_tv(typval_T *varp);
 varnumber_T tv_get_number(typval_T *varp);
 varnumber_T tv_get_number_chk(typval_T *varp, int *denote);
+varnumber_T tv_get_bool(typval_T *varp);
 float_T tv_get_float(typval_T *varp);
 char_u *tv_get_string(typval_T *varp);
 char_u *tv_get_string_buf(typval_T *varp, char_u *buf);
diff --git a/src/typval.c b/src/typval.c
index 406a193..053f300 100644
--- a/src/typval.c
+++ b/src/typval.c
@@ -169,24 +169,8 @@
 	CLEAR_POINTER(varp);
 }
 
-/*
- * Get the number value of a variable.
- * If it is a String variable, uses vim_str2nr().
- * For incompatible types, return 0.
- * tv_get_number_chk() is similar to tv_get_number(), but informs the
- * caller of incompatible types: it sets *denote to TRUE if "denote"
- * is not NULL or returns -1 otherwise.
- */
-    varnumber_T
-tv_get_number(typval_T *varp)
-{
-    int		error = FALSE;
-
-    return tv_get_number_chk(varp, &error);	// return 0L on error
-}
-
-    varnumber_T
-tv_get_number_chk(typval_T *varp, int *denote)
+    static varnumber_T
+tv_get_bool_or_number_chk(typval_T *varp, int *denote, int want_bool)
 {
     varnumber_T	n = 0L;
 
@@ -221,7 +205,7 @@
 	    break;
 	case VAR_BOOL:
 	case VAR_SPECIAL:
-	    if (in_vim9script())
+	    if (!want_bool && in_vim9script())
 	    {
 		emsg(_("E611: Using a Special as a Number"));
 		break;
@@ -253,6 +237,39 @@
     return n;
 }
 
+/*
+ * Get the number value of a variable.
+ * If it is a String variable, uses vim_str2nr().
+ * For incompatible types, return 0.
+ * tv_get_number_chk() is similar to tv_get_number(), but informs the
+ * caller of incompatible types: it sets *denote to TRUE if "denote"
+ * is not NULL or returns -1 otherwise.
+ */
+    varnumber_T
+tv_get_number(typval_T *varp)
+{
+    int		error = FALSE;
+
+    return tv_get_number_chk(varp, &error);	// return 0L on error
+}
+
+    varnumber_T
+tv_get_number_chk(typval_T *varp, int *denote)
+{
+    return tv_get_bool_or_number_chk(varp, denote, FALSE);
+}
+
+/*
+ * Get the boolean value of "varp".  This is like tv_get_number_chk(),
+ * but in Vim9 script accepts Number and Bool.
+ */
+    varnumber_T
+tv_get_bool(typval_T *varp)
+{
+    return tv_get_bool_or_number_chk(varp, NULL, TRUE);
+
+}
+
 #ifdef FEAT_FLOAT
     float_T
 tv_get_float(typval_T *varp)
diff --git a/src/version.c b/src/version.c
index afd3aaa..83af396 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1475,
+/**/
     1474,
 /**/
     1473,