Index: clang/lib/Driver/ToolChains/CommonArgs.cpp
===================================================================
--- clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -358,8 +358,9 @@
                           ArgStringList &CmdArgs, const InputInfo &Output,
                           const InputInfo &Input, bool IsThinLTO) {
   const char *Linker = Args.MakeArgString(ToolChain.GetLinkerPath());
-  if (llvm::sys::path::filename(Linker) != "ld.lld" &&
-      llvm::sys::path::stem(Linker) != "ld.lld") {
+  bool UseLLD = (llvm::sys::path::filename(Linker) == "ld.lld" ||
+                 llvm::sys::path::stem(Linker) == "ld.lld");
+  if (UseLLD) {
     // Tell the linker to load the plugin. This has to come before
     // AddLinkerInputs as gold requires -plugin to come before any -plugin-opt
     // that -Wl might forward.
@@ -381,6 +382,22 @@
     CmdArgs.push_back(Args.MakeArgString(Plugin));
   }
 
+  // Silence warning for "clang -mllvm ...".
+  for (const Arg *A : Args.filtered(options::OPT_mllvm)) {
+    A->claim();
+
+    // Pass llvm options to lld.
+    if (!UseLLD)
+      continue;
+
+    // FIXME: This is now deprecated and should be removed.
+    if (StringRef(A->getValue(0)) == "-disable-llvm-optzns") {
+      CmdArgs.push_back("-disable-llvm-optzns");
+    } else {
+      A->render(Args, CmdArgs);
+    }
+  }
+
   // Try to pass driver level flags relevant to LTO code generation down to
   // the plugin.