examples: add a Makefile for C++ short examples

* examples/c++/Makefile: New.
* examples/c++/local.mk, examples/c++/README: Adjust.

examples/c++/Makefile

@@ -0,0 +1,21 @@
+# This Makefile is designed to be simple and readable.  It does not
+# aim at portability.  It requires GNU Make.
+
+BISON = bison
+CXX = g++
+CXXFLAGS =
+PROGS = simple variant variant-11
+
+simple: CXXFLAGS = -std=c++14
+variant-11: CXXFLAGS = -std=c++11
+
+all: $(PROGS)
+
+%.cc %.hh: %.yy
+	$(BISON) $(BISONFLAGS) -o $*.cc $<
+
+%: %.cc
+	$(CXX) $(CXXFLAGS) -o$@ $<
+
+clean:
+	rm -f $(PROGS:=.cc) $(PROGS)