patch 8.2.1981: MinGW: parallel compilation might fail

Problem:    MinGW: parallel compilation might fail.
Solution:   Add dependencies on $(OUTDIR). (Masamichi Abe, closes #7287)
diff --git a/src/Make_cyg_ming.mak b/src/Make_cyg_ming.mak
index 75021cc..498f34e 100644
--- a/src/Make_cyg_ming.mak
+++ b/src/Make_cyg_ming.mak
@@ -1055,6 +1055,12 @@
 uninstall.exe: uninstall.c dosinst.h version.h
 	$(CC) $(CFLAGS) -o uninstall.exe uninstall.c $(LIB) -lole32
 
+$(OBJ): $(OUTDIR)
+
+$(EXEOBJG): $(OUTDIR)
+
+$(EXEOBJC): $(OUTDIR)
+
 ifeq ($(VIMDLL),yes)
 $(TARGET): $(OUTDIR) $(OBJ)
 	$(LINK) $(CFLAGS) $(LFLAGS) -o $@ $(OBJ) $(LIB) -lole32 -luuid -lgdi32 $(LUA_LIB) $(MZSCHEME_LIBDIR) $(MZSCHEME_LIB) $(PYTHONLIB) $(PYTHON3LIB) $(RUBYLIB)
@@ -1280,7 +1286,7 @@
 	$(CC) -c $(CFLAGS) $< -o $@
 
 
-$(PATHDEF_SRC): Make_cyg_ming.mak Make_cyg.mak Make_ming.mak
+$(PATHDEF_SRC): $(OUTDIR) Make_cyg_ming.mak Make_cyg.mak Make_ming.mak
 ifneq (sh.exe, $(SHELL))
 	@echo creating $(PATHDEF_SRC)
 	@echo '/* pathdef.c */' > $(PATHDEF_SRC)
diff --git a/src/version.c b/src/version.c
index d1e174d..3dde5b2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1981,
+/**/
     1980,
 /**/
     1979,