patch 8.2.1573: Vim9: getreg() does not take "true" as argument

Problem:    Vim9: getreg() does not take "true" as argument.
Solution:   Use tv_get_bool_chk().  (closes #6820)

Author: brammool

src/evalfunc.c

@@ -3336,9 +3336,9 @@ f_getreg(typval_T *argvars, typval_T *rettv)
 	error = strregname == NULL;
 	if (argvars[1].v_type != VAR_UNKNOWN)
 	{
-	    arg2 = (int)tv_get_number_chk(&argvars[1], &error);
+	    arg2 = (int)tv_get_bool_chk(&argvars[1], &error);
 	    if (!error && argvars[2].v_type != VAR_UNKNOWN)
-		return_list = (int)tv_get_number_chk(&argvars[2], &error);
+		return_list = (int)tv_get_bool_chk(&argvars[2], &error);
 	}
     }
     else

src/testdir/test_vim9_func.vim

@@ -1503,6 +1503,12 @@ def Test_expand()
   close
 enddef
 
+def Test_getreg()
+  let lines = ['aaa', 'bbb', 'ccc']
+  setreg('a', lines)
+  assert_equal(lines, getreg('a', true, true))
+enddef
+
 def Test_recursive_call()
   assert_equal(6765, Fibonacci(20))
 enddef

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1573,
 /**/
     1572,
 /**/