build: Make clean targets more thorough

Makefile

@@ -111,6 +111,7 @@ test: functionaltest unittest
 clean:
 	+test -d build && $(BUILD_CMD) -C build clean || true
 	$(MAKE) -C src/nvim/testdir clean
+	$(MAKE) -C runtime/doc clean
 
 distclean: clean
 	rm -rf .deps build

runtime/doc/Makefile

@@ -36,5 +36,5 @@ tags.ref tags.html: tags
 	$(AWK) -f maketags.awk tags >tags.html
 
 clean:
-	-rm -f *.html tags.ref $(HTMLS) errors.log
+	-rm -f *.html tags.ref $(HTMLS) errors.log tags
 

src/nvim/testdir/Makefile

@@ -116,6 +116,7 @@ clean:
 	        valgrind.*     \
 	        .*.swp         \
 	        .*.swo         \
+	        .gdbinit       \
 	        del
 
 test1.out: .gdbinit test1.in