patch 8.2.1607: Vim9: getchar() test fails on MS-Windows

Problem:    Vim9: getchar() test fails on MS-Windows.
Solution:   First consume any available input.

Author: brammool

src/testdir/test_vim9_func.vim

@@ -1506,6 +1506,8 @@ def Test_getbufinfo()
 enddef
 
 def Test_getchar()
+  while getchar(0)
+  endwhile
   assert_equal(0, getchar(true))
 enddef
 

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1607,
 /**/
     1606,
 /**/