glr2.cc: add an example

Currently this example crashes on input such as "T (x) + y;".
The same example with glr.c works properly.

* examples/c++/glr/Makefile, examples/c++/glr/README.md,
* examples/c++/glr/c++-types.test, examples/c++/glr/c++-types.yy,
* examples/c++/glr/local.mk, examples/c++/local.mk: New.
Based on examples/c/glr/c++-types.y.

examples/c/glr/Makefile

@@ -1,7 +1,7 @@
 # This Makefile is designed to be simple and readable.  It does not
 # aim at portability.  It requires GNU Make.
 
-BASE = calc
+BASE = c++-types
 BISON = bison
 XSLTPROC = xsltproc
 
@@ -14,7 +14,7 @@ $(BASE): $(BASE).o
 	$(CC) $(CFLAGS) -o $@ $^
 
 run: $(BASE)
-	@echo "Type arithmetic expressions.  Quit with ctrl-d."
+	@echo "Type C++ declarations or expressions.  Quit with ctrl-d."
 	./$<
 
 html: $(BASE).html