Modernize the .ll parsing interface.

* Use StringRef instead of std::string&
* Return a std::unique_ptr<Module> instead of taking an optional module to write
  to (was not really used).
* Use current comment style.
* Use current naming convention.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215989 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/IR/UserTest.cpp b/unittests/IR/UserTest.cpp
index eb07e82..5572424 100644
--- a/unittests/IR/UserTest.cpp
+++ b/unittests/IR/UserTest.cpp
@@ -65,7 +65,7 @@
                              "  ret void\n"
                              "}\n";
   SMDiagnostic Err;
-  Module *M = ParseAssemblyString(ModuleString, nullptr, Err, C);
+  std::unique_ptr<Module> M = parseAssemblyString(ModuleString, Err, C);
 
   Function *F = M->getFunction("f");
   BasicBlock &ExitBB = F->back();