Remove buggy example code from the documentation

Instead point readers to the latest, correct example code in SVN until we find
a way to automatically include example sources into the documentation (or until
someone steps up to maintain these actively).

This ensures that the examples are up-to-date, buildable, and most of all that
readers don't pick up incorrect usage.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200125 91177308-0d34-0410-b5e6-96231b3b80d8

docs/ClangPlugins.rst

@@ -47,70 +47,10 @@ Putting it all together
 =======================
 
 Let's look at an example plugin that prints top-level function names.  This
-example is also checked into the clang repository; please also take a look at
-the latest `checked in version of PrintFunctionNames.cpp
+example is checked into the clang repository; please take a look at
+the `latest version of PrintFunctionNames.cpp
 <http://llvm.org/viewvc/llvm-project/cfe/trunk/examples/PrintFunctionNames/PrintFunctionNames.cpp?view=markup>`_.
 
-.. code-block:: c++
-
-    #include "clang/Frontend/FrontendPluginRegistry.h"
-    #include "clang/AST/ASTConsumer.h"
-    #include "clang/AST/AST.h"
-    #include "clang/Frontend/CompilerInstance.h"
-    #include "llvm/Support/raw_ostream.h"
-    using namespace clang;
-
-    namespace {
-
-    class PrintFunctionsConsumer : public ASTConsumer {
-    public:
-      virtual bool HandleTopLevelDecl(DeclGroupRef DG) {
-        for (DeclGroupRef::iterator i = DG.begin(), e = DG.end(); i != e; ++i) {
-          const Decl *D = *i;
-          if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
-            llvm::errs() << "top-level-decl: \"" << ND->getNameAsString() << "\"\n";
-        }
-
-        return true;
-      }
-    };
-
-    class PrintFunctionNamesAction : public PluginASTAction {
-    protected:
-      ASTConsumer *CreateASTConsumer(CompilerInstance &CI, llvm::StringRef) {
-        return new PrintFunctionsConsumer();
-      }
-
-      bool ParseArgs(const CompilerInstance &CI,
-                     const std::vector<std::string>& args) {
-        for (unsigned i = 0, e = args.size(); i != e; ++i) {
-          llvm::errs() << "PrintFunctionNames arg = " << args[i] << "\n";
-
-          // Example error handling.
-          if (args[i] == "-an-error") {
-            DiagnosticsEngine &D = CI.getDiagnostics();
-            unsigned DiagID = D.getCustomDiagID(
-              DiagnosticsEngine::Error, "invalid argument '" + args[i] + "'");
-            D.Report(DiagID);
-            return false;
-          }
-        }
-        if (args.size() && args[0] == "help")
-          PrintHelp(llvm::errs());
-
-        return true;
-      }
-      void PrintHelp(llvm::raw_ostream& ros) {
-        ros << "Help for PrintFunctionNames plugin goes here\n";
-      }
-
-    };
-
-    }
-
-    static FrontendPluginRegistry::Add<PrintFunctionNamesAction>
-    X("print-fns", "print function names");
-
 Running the plugin
 ==================