Fix build warnings

src/IceConverter.cpp

 //===- subzero/src/IceConverter.cpp - Converts LLVM to Ice  ---------------===//
 //
 //                        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 LLVM to ICE converter.
@@ skipping 571 matching lines @@
       Ice::Inst *Inst = convertInstruction(&II);
       Node->appendInst(Inst);
     }
     return Node;
   }
 
   void validateIntrinsicCall(const Ice::InstCall *Call,
                              const Ice::Intrinsics::FullIntrinsicInfo *I) {
     Ice::SizeT ArgIndex = 0;
     switch (I->validateCall(Call, ArgIndex)) {
-    default:
-      report_fatal_error("Unknown validation error for intrinsic call");
-      break;
     case Ice::Intrinsics::IsValidCall:
       break;
     case Ice::Intrinsics::BadReturnType: {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Intrinsic call expects return type " << I->getReturnType()
              << ". Found: " << Call->getReturnType();
       report_fatal_error(StrBuf.str());
       break;
     }
@@ skipping 287 matching lines @@
     Cfg *Fcn = FunctionConverter.convertFunction(&I);
     translateFcn(Fcn);
     if (ALLOW_DUMP && Ctx->getFlags().TimeEachFunction)
       Ctx->popTimer(TimerID, StackID);
   }
 
   emitConstants();
 }
 
 } // end of namespace Ice