S390: Remove more dead code now that legacy const is gone

src/full-codegen/s390/full-codegen-s390.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_S390
 
 #include "src/ast/scopes.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 725 matching lines @@
         // No write barrier since the_hole_value is in old space.
         PrepareForBailoutForId(proxy->id(), BailoutState::NO_REGISTERS);
       }
       break;
 
     case VariableLocation::LOOKUP: {
       Comment cmnt(masm_, "[ VariableDeclaration");
       __ mov(r4, Operand(variable->name()));
       // Declaration nodes are always introduced in one of four modes.
       DCHECK(IsDeclaredVariableMode(mode));
-      // Push initial value, if any.
-      // Note: For variables we must not push an initial value (such as
-      // 'undefined') because we may have a (legal) redeclaration and we
-      // must not destroy the current value.
-      if (hole_init) {
-        __ LoadRoot(r2, Heap::kTheHoleValueRootIndex);
-      } else {
-        __ LoadSmiLiteral(r2, Smi::FromInt(0));  // Indicates no initial value.
-      }
+      DCHECK(!hole_init);
+      __ LoadSmiLiteral(r2, Smi::FromInt(0));  // Indicates no initial value.
       __ Push(r4, r2);
       __ Push(Smi::FromInt(variable->DeclarationPropertyAttributes()));
       __ CallRuntime(Runtime::kDeclareLookupSlot);
       PrepareForBailoutForId(proxy->id(), BailoutState::NO_REGISTERS);
       break;
     }
   }
 }
 
 void FullCodeGenerator::VisitFunctionDeclaration(
@@ skipping 2950 matching lines @@
   DCHECK(kOSRBranchInstruction == br_instr);
 
   DCHECK(interrupt_address ==
          isolate->builtins()->OnStackReplacement()->entry());
   return ON_STACK_REPLACEMENT;
 }
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_TARGET_ARCH_S390