add static_csharp rule to Makefile

Makefile

@@ -1381,6 +1381,8 @@ static_c: pc_c pc_c_unsecure cache.mk  $(LIBDIR)/$(CONFIG)/libaddress_sorting.a
 
 static_cxx: pc_cxx pc_cxx_unsecure cache.mk  $(LIBDIR)/$(CONFIG)/libgrpc++.a $(LIBDIR)/$(CONFIG)/libgrpc++_cronet.a $(LIBDIR)/$(CONFIG)/libgrpc++_error_details.a $(LIBDIR)/$(CONFIG)/libgrpc++_reflection.a $(LIBDIR)/$(CONFIG)/libgrpc++_unsecure.a $(LIBDIR)/$(CONFIG)/libgrpcpp_channelz.a
 
+static_csharp: static_c  $(LIBDIR)/$(CONFIG)/libgrpc_csharp_ext.a
+
 shared: shared_c shared_cxx
 
 shared_c: pc_c pc_c_unsecure cache.mk $(LIBDIR)/$(CONFIG)/$(SHARED_PREFIX)address_sorting$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/$(SHARED_PREFIX)gpr$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/$(SHARED_PREFIX)grpc$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/$(SHARED_PREFIX)grpc_cronet$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE) $(LIBDIR)/$(CONFIG)/$(SHARED_PREFIX)grpc_unsecure$(SHARED_VERSION_CORE).$(SHARED_EXT_CORE)

templates/Makefile.template

@@ -921,6 +921,16 @@
   % endfor
 
 
+  static_csharp: static_c \
+  % for lib in libs:
+  % if 'Makefile' in lib.get('build_system', ['Makefile']):
+  % if lib.build == 'all' and lib.language == 'csharp':
+   $(LIBDIR)/$(CONFIG)/lib${lib.name}.a\
+  % endif
+  % endif
+  % endfor
+
+
   shared: shared_c shared_cxx
 
   shared_c: pc_c pc_c_unsecure cache.mk\