Add ENABLE_CXX11 and ENABLE_WERROR to Makefile.llvm.rules for sample project. They were previously added to Makefile.llvm.config.in but the consumption was missing

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168685 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/projects/sample/Makefile.llvm.rules b/projects/sample/Makefile.llvm.rules
index 7ed1c1b..89b9e56 100644
--- a/projects/sample/Makefile.llvm.rules
+++ b/projects/sample/Makefile.llvm.rules
@@ -250,6 +250,15 @@
   LD.Flags +=  -stdlib=libc++
 endif
 
+ifeq ($(ENABLE_CXX11),1)
+  CXX.Flags += -std=c++11
+endif
+
+ifeq ($(ENABLE_WERROR),1)
+  CXX.Flags += -Werror
+  C.Flags += -Werror
+endif
+
 ifeq ($(ENABLE_PROFILING),1)
   BuildMode := $(BuildMode)+Profile
   CXX.Flags := $(filter-out -fomit-frame-pointer,$(CXX.Flags)) -pg -g