patch 8.2.1611: Vim9: cannot pass "true" to nr2char()

Problem:    Vim9: cannot pass "true" to nr2char().
Solution:   use tv_get_bool_chk(). (closes #6878)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index b4e4220..2a82812 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -5874,7 +5874,7 @@
 	int	utf8 = 0;
 
 	if (argvars[1].v_type != VAR_UNKNOWN)
-	    utf8 = (int)tv_get_number_chk(&argvars[1], NULL);
+	    utf8 = (int)tv_get_bool_chk(&argvars[1], NULL);
 	if (utf8)
 	    buf[utf_char2bytes((int)tv_get_number(&argvars[0]), buf)] = NUL;
 	else
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index 84fc7c9..b3b6b32 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -1529,6 +1529,10 @@
   assert_equal(s, list2str(l, true))
 enddef
 
+def Test_nr2char()
+  assert_equal('a', nr2char(97, true))
+enddef
+
 def Fibonacci(n: number): number
   if n < 2
     return n
diff --git a/src/version.c b/src/version.c
index a8cf168..bcece94 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1611,
+/**/
     1610,
 /**/
     1609,