Nuke SetUpBuildDumpLog.

Also, it was the only reason that `argc` and `argv` were being passed
into createDiagnostics, so remove those parameters and clean up callers.

llvm-svn: 172945
diff --git a/clang/unittests/Frontend/FrontendActionTest.cpp b/clang/unittests/Frontend/FrontendActionTest.cpp
index e70c3b8..bcb340d 100644
--- a/clang/unittests/Frontend/FrontendActionTest.cpp
+++ b/clang/unittests/Frontend/FrontendActionTest.cpp
@@ -60,7 +60,7 @@
   invocation->getTargetOpts().Triple = "i386-unknown-linux-gnu";
   CompilerInstance compiler;
   compiler.setInvocation(invocation);
-  compiler.createDiagnostics(0, NULL);
+  compiler.createDiagnostics();
 
   TestASTFrontendAction test_action;
   ASSERT_TRUE(compiler.ExecuteAction(test_action));