Subzero: Allow overriding command-line args from the browser.

src/IceCompileServer.cpp

Index: src/IceCompileServer.cpp
diff --git a/src/IceCompileServer.cpp b/src/IceCompileServer.cpp
index 0ed98ba5f72b79cc3906b5f40e0e478873b697dd..e700b1ee125674aecefa28ac0db77bbe87479675 100644
--- a/src/IceCompileServer.cpp
+++ b/src/IceCompileServer.cpp
@@ -89,6 +89,8 @@ std::unique_ptr<Ostream> makeStream(const std::string &Filename,
                                     std::error_code &EC) {
   if (Filename == "-") {
     return std::unique_ptr<Ostream>(new llvm::raw_os_ostream(std::cout));
+  } else if (Filename == "/dev/stderr") {
+    return std::unique_ptr<Ostream>(new llvm::raw_os_ostream(std::cerr));
   } else {
     return std::unique_ptr<Ostream>(
         new llvm::raw_fd_ostream(Filename, EC, llvm::sys::fs::F_None));