Subzero: Support non-IRT immediate calls with -filetype=iasm.

src/IceFixups.cpp

 //===- subzero/src/IceFixups.cpp - Implementation of Assembler Fixups -----===//
 //
 //                        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 AssemblerFixup class, a very basic
@@ skipping 28 matching lines @@
       Str << Ctx->mangleName(CR->getName());
   } else {
     // NOTE: currently only float/doubles are put into constant pools.
     // In the future we may put integers as well.
     assert(llvm::isa<ConstantFloat>(C) || llvm::isa<ConstantDouble>(C));
     C->emitPoolLabel(Str);
   }
   return Str.str();
 }
 
-void AssemblerFixup::emit(GlobalContext *Ctx) const {
+void AssemblerFixup::emit(GlobalContext *Ctx, RelocOffsetT BaseOffset) const {
+  if (!ALLOW_DUMP)
+    return;
   Ostream &Str = Ctx->getStrEmit();
-  // TODO(jvoung): Not yet clear how to emit a relocation against
-  // the null symbol.
-  assert(!isNullSymbol());
-  Str << symbol(Ctx);
-  RelocOffsetT Offset = offset();
+  if (isNullSymbol())
+    Str << "__Sz_AbsoluteZero";
+  else
+    Str << symbol(Ctx);
+  RelocOffsetT Offset = offset() + BaseOffset;
   if (Offset)
     Str << " + " << Offset;
 }
 
 } // end of namespace Ice