Remove test52

Test52 does nothing on UNIX. And vim on Windows performs mbyte-conversion
between Unicode and code page using Windows API(See :h mbyte-conversion).
Test52 seems to be testing its functionality. In neovim, the conversion
function by Windows API has been removed. Therefore, there is no point
in doing this test.

src/nvim/testdir/Makefile

@@ -16,7 +16,6 @@ export TMPDIR := $(abspath ../../../Xtest-tmpdir)
 SCRIPTS_DEFAULT = \
 	test42.out             \
 	test48.out             \
-	test52.out             \
 	test64.out             \
 
 ifneq ($(OS),Windows_NT)

src/nvim/testdir/test52.in

@@ -1,64 +0,0 @@
-Tests for reading and writing files with conversion for Win32.
-
-STARTTEST
-:" make this a dummy test for non-Win32 systems
-:if !has("win32") | e! test.ok | wq! test.out | endif
-:"
-:" write tests:
-:" combine three values for 'encoding' with three values for 'fileencoding'
-:" also write files for read tests
-/^1
-:set encoding=utf-8
-:.w! ++enc=utf-8 test.out
-:.w ++enc=cp1251 >>test.out
-:.w ++enc=cp866 >>test.out
-:.w! ++enc=utf-8 Xutf8
-/^2
-:set encoding=cp1251
-:.w ++enc=utf-8 >>test.out
-:.w ++enc=cp1251 >>test.out
-:.w ++enc=cp866 >>test.out
-:.w! ++enc=cp1251 Xcp1251
-/^3
-:set encoding=cp866
-:.w ++enc=utf-8 >>test.out
-:.w ++enc=cp1251 >>test.out
-:.w ++enc=cp866 >>test.out
-:.w! ++enc=cp866 Xcp866
-:"
-:" read three 'fileencoding's with utf-8 'encoding'
-:set encoding=utf-8 fencs=utf-8,cp1251
-:e Xutf8
-:.w ++enc=utf-8 >>test.out
-:e Xcp1251
-:.w ++enc=utf-8 >>test.out
-:set fencs=utf-8,cp866
-:e Xcp866
-:.w ++enc=utf-8 >>test.out
-:"
-:" read three 'fileencoding's with cp1251 'encoding'
-:set encoding=utf-8 fencs=utf-8,cp1251
-:e Xutf8
-:.w ++enc=cp1251 >>test.out
-:e Xcp1251
-:.w ++enc=cp1251 >>test.out
-:set fencs=utf-8,cp866
-:e Xcp866
-:.w ++enc=cp1251 >>test.out
-:"
-:" read three 'fileencoding's with cp866 'encoding'
-:set encoding=cp866 fencs=utf-8,cp1251
-:e Xutf8
-:.w ++enc=cp866 >>test.out
-:e Xcp1251
-:.w ++enc=cp866 >>test.out
-:set fencs=utf-8,cp866
-:e Xcp866
-:.w ++enc=cp866 >>test.out
-:"
-:qa!
-ENDTEST
-
-1 utf-8 text: ДлÑ<C2BB> Vim version 6.2.  ПоÑ<C2BE>леднее изменение: 1970 Jan 01
-2 cp1251 text: Äëÿ Vim version 6.2.  Ïîñëåäíåå èçìåíåíèå: 1970 Jan 01
-3 cp866 text: „«ï Vim version 6.2.  <20>®á«¥¤­¥¥ ¨§¬¥­¥­¨¥: 1970 Jan 01

src/nvim/testdir/test52.ok

@@ -1,18 +0,0 @@
-1 utf-8 text: ДлÑ<C2BB> Vim version 6.2.  ПоÑ<C2BE>леднее изменение: 1970 Jan 01
-1 utf-8 text: Äëÿ Vim version 6.2.  Ïîñëåäíåå èçìåíåíèå: 1970 Jan 01
-1 utf-8 text: „«ï Vim version 6.2.  <20>®á«¥¤­¥¥ ¨§¬¥­¥­¨¥: 1970 Jan 01
-2 cp1251 text: ДлÑ<C2BB> Vim version 6.2.  ПоÑ<C2BE>леднее изменение: 1970 Jan 01
-2 cp1251 text: Äëÿ Vim version 6.2.  Ïîñëåäíåå èçìåíåíèå: 1970 Jan 01
-2 cp1251 text: „«ï Vim version 6.2.  <20>®á«¥¤­¥¥ ¨§¬¥­¥­¨¥: 1970 Jan 01
-3 cp866 text: ДлÑ<C2BB> Vim version 6.2.  ПоÑ<C2BE>леднее изменение: 1970 Jan 01
-3 cp866 text: Äëÿ Vim version 6.2.  Ïîñëåäíåå èçìåíåíèå: 1970 Jan 01
-3 cp866 text: „«ï Vim version 6.2.  <20>®á«¥¤­¥¥ ¨§¬¥­¥­¨¥: 1970 Jan 01
-1 utf-8 text: ДлÑ<C2BB> Vim version 6.2.  ПоÑ<C2BE>леднее изменение: 1970 Jan 01
-2 cp1251 text: ДлÑ<C2BB> Vim version 6.2.  ПоÑ<C2BE>леднее изменение: 1970 Jan 01
-3 cp866 text: ДлÑ<C2BB> Vim version 6.2.  ПоÑ<C2BE>леднее изменение: 1970 Jan 01
-1 utf-8 text: Äëÿ Vim version 6.2.  Ïîñëåäíåå èçìåíåíèå: 1970 Jan 01
-2 cp1251 text: Äëÿ Vim version 6.2.  Ïîñëåäíåå èçìåíåíèå: 1970 Jan 01
-3 cp866 text: Äëÿ Vim version 6.2.  Ïîñëåäíåå èçìåíåíèå: 1970 Jan 01
-1 utf-8 text: „«ï Vim version 6.2.  <20>®á«¥¤­¥¥ ¨§¬¥­¥­¨¥: 1970 Jan 01
-2 cp1251 text: „«ï Vim version 6.2.  <20>®á«¥¤­¥¥ ¨§¬¥­¥­¨¥: 1970 Jan 01
-3 cp866 text: „«ï Vim version 6.2.  <20>®á«¥¤­¥¥ ¨§¬¥­¥­¨¥: 1970 Jan 01