patch 8.1.1213: "make clean" in top dir does not cleanup indent test output

Problem:    "make clean" in top dir does not cleanup indent test output.
Solution:   Clean the indent test output.  Do not rely on the vim executable
            for that. (closes #4307)
diff --git a/Makefile b/Makefile
index 16fc84c..6ee3b1c 100644
--- a/Makefile
+++ b/Makefile
@@ -43,13 +43,18 @@
 	@if test "$@" = "test"; then \
 		$(MAKE) indenttest; \
 	fi
+	@# When the target is "clean" also clean for the indent tests.
+	@if test "$@" = "clean" -o "$@" = "distclean" -o "$@" = "testclean"; then \
+		cd runtime/indent && \
+			$(MAKE) clean; \
+	fi
 
 # Executable used for running the indent tests.
 VIM_FOR_INDENTTEST = ../../src/vim
 
 indenttest:
 	cd runtime/indent && \
-		$(MAKE) clean VIM="$(VIM_FOR_INDENTTEST)" && \
+		$(MAKE) clean && \
 		$(MAKE) test VIM="$(VIM_FOR_INDENTTEST)"
 		
 
diff --git a/runtime/indent/Makefile b/runtime/indent/Makefile
index 1917e46..d192605 100644
--- a/runtime/indent/Makefile
+++ b/runtime/indent/Makefile
@@ -11,4 +11,4 @@
 
 
 clean:
-	VIMRUNTIME=$(VIMRUNTIME) $(VIM) --clean --not-a-term -u testdir/cleantest.vim
+	rm -f testdir/*.fail testdir/*.out
diff --git a/runtime/indent/testdir/cleantest.vim b/runtime/indent/testdir/cleantest.vim
deleted file mode 100644
index 69c0a1d..0000000
--- a/runtime/indent/testdir/cleantest.vim
+++ /dev/null
@@ -1,11 +0,0 @@
-" Only do this with the +eval feature
-if 1
-
-  " Deletes all the test output files: *.fail and *.out
-  for fname in glob('testdir/*.out', 1, 1) + glob('testdir/*.fail', 1, 1)
-    call delete(fname)
-  endfor
-
-endif
-
-quit
diff --git a/src/version.c b/src/version.c
index 704ff54..88763e5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1213,
+/**/
     1212,
 /**/
     1211,