patch 9.0.1654: MS-Windows: test for default 'viewdir' fails

Problem:    MS-Windows: test for default 'viewdir' fails.
Solution:   Escape the pattern.

src/testdir/test_mksession.vim

@@ -1265,7 +1265,8 @@ endfunc
 " Test default 'viewdir' value
 func Test_mkview_default_home()
   if has('win32')
-    call assert_match('^' .. $ORIGHOME .. '/vimfiles', &viewdir)
+    " use escape() to handle backslash path separators
+    call assert_match('^' .. escape($ORIGHOME, '\') .. '/vimfiles', &viewdir)
   elseif has('unix')
     call assert_match('^' .. $ORIGHOME .. '/.vim', &viewdir)
   elseif has('amiga')

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1654,
 /**/
     1653,
 /**/