Handle ARM "ret void" and function alignment with proper padding.

src/IceCompileServer.cpp

 //===- subzero/src/IceCompileServer.cpp - Compile server ------------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines the basic commandline-based compile server.
 //
 //===----------------------------------------------------------------------===//
 
 #include <fstream>
 #include <iostream>
 #include <thread>
 
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/raw_os_ostream.h"
+#include "llvm/Support/Signals.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/StreamingMemoryObject.h"
 
 #include "IceClFlags.h"
 #include "IceClFlagsExtra.h"
 #include "IceCompileServer.h"
 #include "IceELFStreamer.h"
 #include "IceGlobalContext.h"
 
 namespace Ice {
@@ skipping 12 matching lines @@
 
 ErrorCodes getReturnValue(const Ice::ClFlagsExtra &Flags, ErrorCodes Val) {
   if (Flags.getAlwaysExitSuccess())
     return EC_None;
   return Val;
 }
 
 } // end of anonymous namespace
 
 void CLCompileServer::run() {
+  if (ALLOW_DUMP) {
+    llvm::sys::PrintStackTraceOnErrorSignal();
+  }
   ClFlags::parseFlags(argc, argv);
   ClFlags Flags;
   ClFlagsExtra ExtraFlags;
   ClFlags::getParsedClFlags(Flags);
   ClFlags::getParsedClFlagsExtra(ExtraFlags);
 
   std::error_code EC;
   std::unique_ptr<Ostream> Ls = makeStream(ExtraFlags.getLogFilename(), EC);
   if (EC) {
     llvm::report_fatal_error("Unable to open log file");
@@ skipping 51 matching lines @@
     });
     CompileThread.join();
   } else {
     getCompiler().run(ExtraFlags, *Ctx.get(), std::move(InputStream));
   }
   transferErrorCode(getReturnValue(
       ExtraFlags, static_cast<ErrorCodes>(Ctx->getErrorStatus()->value())));
 }
 
 } // end of namespace Ice