Install notion of diagnostic handler into PNaCl bitcode readers.

tools/llvm-dis/llvm-dis.cpp

Index: tools/llvm-dis/llvm-dis.cpp
diff --git a/tools/llvm-dis/llvm-dis.cpp b/tools/llvm-dis/llvm-dis.cpp
index dbf0c9c7b3c3440f4fddc91b550ebef9189ee1fd..d9a52e3aa75418341089b7a38583404cf2dbdf4a 100644
--- a/tools/llvm-dis/llvm-dis.cpp
+++ b/tools/llvm-dis/llvm-dis.cpp
@@ -188,9 +188,10 @@ int main(int argc, char **argv) {
         break;
       }
       case PNaClFormat: {
-        M.reset(getNaClStreamedBitcodeModule(
-            DisplayFilename, Buffer.release(), Context, &errs(),
-            &ErrorMessage));
+        DiagnosticHandlerFunction DiagnosticHandler = nullptr;
+        M.reset(getNaClStreamedBitcodeModule(DisplayFilename, Buffer.release(),
+                                             Context, DiagnosticHandler,

[Derek Schuff, 2015/08/24 22:46:04]

why not just pass nullptr here instead of creating an explicit DH?

[Derek Schuff, 2015/08/25 17:06:04]

From in-person conversations, this is just for self-documenting. Can we use the
LLVM style for that, i.e.

M.reset(getNaClStreamedBitcodeModule(DisplayFilename, Buffer.release(),
        Context, /* DiagnosticHandler = */ nullptr,

(here and also in pnacl-llc)

[Karl, 2015/08/26 17:39:48]

Done.

+                                             &ErrorMessage));
         if(M.get()) {
           if (std::error_code EC = M->materializeAllPermanently()) {
             FoundErrors = true;