patch 8.0.0553: toupper/tolower test fails on Mac

Problem:    Toupper/tolower test with Turkish locale fails on Mac.
Solution:   Skip the test on Mac.

src/testdir/test_normal.vim

@@ -1603,7 +1603,9 @@ fun! Test_normal30_changecase()
   norm! V~
   call assert_equal('THIS IS A simple test: äüöss', getline('.'))
 
-  " Turkish ASCII turns to multi-byte.
+  " Turkish ASCII turns to multi-byte.  On Mac the Turkish locale is available
+  " but toupper()/tolower() don't do the right thing.
+  if !has('mac')
     try
       lang tr_TR.UTF-8
       set casemap=
@@ -1622,6 +1624,7 @@ fun! Test_normal30_changecase()
       " can't use Turkish locale
       throw 'Skipped: Turkish locale not available'
     endtry
+  endif
 
   " clean up
   bw!

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    553,
 /**/
     552,
 /**/