Subzero: Add basic ELFObjectWriter (text section, symtab, strtab, headers)

src/IceTargetLoweringX8632.cpp

 //===- subzero/src/IceTargetLoweringX8632.cpp - x86-32 lowering -----------===//
 //
 //                        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 TargetLoweringX8632 class, which
@@ skipping 4546 matching lines @@
 }
 
 void ConstantUndef::emit(GlobalContext *) const {
   llvm_unreachable("undef value encountered by emitter.");
 }
 
 TargetGlobalInitX8632::TargetGlobalInitX8632(GlobalContext *Ctx)
     : TargetGlobalInitLowering(Ctx) {}
 
 void TargetGlobalInitX8632::lower(const VariableDeclaration &Var) {
+  // TODO(jvoung): handle this without text.
+  if (Ctx->getFlags().UseELFWriter)
+    return;
 
   Ostream &Str = Ctx->getStrEmit();
 
   const VariableDeclaration::InitializerListType &Initializers =
       Var.getInitializers();
 
   // If external and not initialized, this must be a cross test.
   // Don't generate a declaration for such cases.
   bool IsExternal = Var.isExternal() || Ctx->getFlags().DisableInternal;
   if (IsExternal && !Var.hasInitializer()) return;
@@ skipping 73 matching lines @@
   } else if (IsConstant || IsExternal)
     Str << "\t.zero\t" << Size << "\n";
   // Size is part of .comm.
 
   if (IsConstant || HasNonzeroInitializer || IsExternal)
     Str << "\t.size\t" << MangledName << ", " << Size << "\n";
   // Size is part of .comm.
 }
 
 } // end of namespace Ice