Subzero: Fixes for Hello World and bisection debugging.

src/IceCfg.cpp

 //===- subzero/src/IceCfg.cpp - Control flow graph implementation ---------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the Cfg class, including constant pool
@@ skipping 291 matching lines @@
     Str << "# $LLVM_BIN_PATH/llvm-mc"
         << " -arch=x86"
         << " -x86-asm-syntax=intel"
         << " -filetype=obj"
         << " -o=MyObj.o"
         << "\n\n";
   }
   Str << "\t.text\n";
   IceString MangledName = getContext()->mangleName(getFunctionName());
   if (Ctx->getFlags().FunctionSections)
-    Str << "\t.section\t.text." << MangledName << "\n";
+    Str << "\t.section\t.text." << MangledName << ",\"ax\",@progbits\n";
   if (!getInternal()) {
     Str << "\t.globl\t" << MangledName << "\n";
     Str << "\t.type\t" << MangledName << ",@function\n";
   }
   for (NodeList::const_iterator I = Nodes.begin(), E = Nodes.end(); I != E;
        ++I) {
     (*I)->emit(this);
   }
   Str << "\n";
   T_emit.printElapsedUs(Ctx, "emit()");
@@ skipping 45 matching lines @@
   for (NodeList::const_iterator I = Nodes.begin(), E = Nodes.end(); I != E;
        ++I) {
     (*I)->dump(this);
   }
   if (getContext()->isVerbose(IceV_Instructions)) {
     Str << "}\n";
   }
 }
 
 } // end of namespace Ice