Remove set but otherwise unused variable

Recent Clang versions have enhanced -Wunused-but-set-variable which now
warns about this.

Bug: chromium:1309955
Change-Id: If5c1ce77bdcdb1e04eed4ae9e10ee1d7f2e8658d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3563139
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Hans Wennborg <hans@chromium.org>
Auto-Submit: Hans Wennborg <hans@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79693}

src/compiler/backend/instruction-selector.cc

@@ -1170,6 +1170,7 @@ void InstructionSelector::InitializeCallBuffer(Node* call, CallBuffer* buffer,
   }
   DCHECK_EQ(input_count, buffer->instruction_args.size() + pushed_count -
                              frame_state_entries);
+  USE(pushed_count);
   if (V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK && is_tail_call &&
       stack_param_delta != 0) {
     // For tail calls that change the size of their parameter list and keep

src/compiler/linkage.cc

@@ -470,6 +470,7 @@ CallDescriptor* Linkage::GetStubCallDescriptor(
       num_returns++;
     }
   }
+  USE(num_fp_returns);
 
   // Add parameters in registers and on the stack.
   for (int i = 0; i < js_parameter_count; i++) {

src/compiler/verifier.cc

@@ -155,6 +155,7 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
   // consumed as an effect input somewhere else.
   // TODO(mvstanton): support this kind of verification for Wasm compiles, too.
   if (code_type != kWasm && node->op()->EffectOutputCount() > 0) {
+#ifdef DEBUG
     int effect_edges = 0;
     for (Edge edge : node->use_edges()) {
       if (all.IsLive(edge.from()) && NodeProperties::IsEffectEdge(edge)) {
@@ -162,6 +163,7 @@ void Verifier::Visitor::Check(Node* node, const AllNodes& all) {
       }
     }
     DCHECK_GT(effect_edges, 0);
+#endif
   }
 
   // Verify that frame state has been inserted for the nodes that need it.

src/heap/mark-compact.cc

@@ -4804,6 +4804,7 @@ size_t MarkCompactCollector::PostProcessEvacuationCandidates() {
     }
   }
   DCHECK_EQ(aborted_pages_verified, aborted_pages);
+  USE(aborted_pages_verified);
   return aborted_pages;
 }
 

src/trap-handler/handler-outside.cc

@@ -89,6 +89,7 @@ void ValidateCodeObjects() {
   }
 
   // Check the validity of the free list.
+#ifdef DEBUG
   size_t free_count = 0;
   for (size_t i = gNextCodeObject; i != gNumCodeObjects;
        i = gCodeObjects[i].next_free) {
@@ -106,6 +107,7 @@ void ValidateCodeObjects() {
     }
   }
   TH_DCHECK(free_count == free_count2);
+#endif
 }
 }  // namespace
 

src/wasm/function-body-decoder.cc

@@ -311,6 +311,7 @@ bool PrintRawWasmCode(AccountingAllocator* allocator, const FunctionBody& body,
     ++line_nr;
   }
   DCHECK(!line_numbers || line_numbers->size() == static_cast<size_t>(line_nr));
+  USE(line_nr);
 
   return decoder.ok();
 }

src/wasm/module-instantiate.cc

@@ -1637,6 +1637,7 @@ int InstanceBuilder::ProcessImports(Handle<WasmInstanceObject> instance) {
           return -1;
         }
         num_imported_tables++;
+        USE(num_imported_tables);
         break;
       }
       case kExternalMemory: {