patch 8.1.0723: cannot easily run specific test when in src/testdir
Problem: Cannot run specific test when in src/testdir the same was as in
the src directory.
Solution: Move build rule to src/testdir/Makefile.
diff --git a/src/Make_mvc.mak b/src/Make_mvc.mak
index 00c4f24..baf0b7d 100644
--- a/src/Make_mvc.mak
+++ b/src/Make_mvc.mak
@@ -694,6 +694,7 @@
!endif # DEBUG
!include Make_all.mak
+!include testdir\Make_all.mak
INCL = vim.h alloc.h arabic.h ascii.h ex_cmds.h farsi.h feature.h globals.h \
keymap.h macros.h option.h os_dos.h os_win32.h proto.h regexp.h \