Revert of [turbofan] Add --csa-verify flag that enables machine graph...

Revert of [turbofan] Add --csa-verify flag that enables machine graph verification of code stubs. (patchset #2 id:60001 of https://codereview.chromium.org/2551933002/ )

Reason for revert:
Broke nosnap build: https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20nosnap%20-%20debug/builds/10689

Original issue's description:
> [turbofan] Add --csa-verify flag that enables machine graph verification of code stubs.
>
> The flag must be used only by CodeStubAssemblerGraphsCorrectness cctest for now
> and once all the verification issues are fixed the flag will be enabled in debug
> mode by default.
>
> BUG=
>
> Committed: https://crrev.com/292b3548f6d02b964b4afe3e05f89c0681fa5620
> Cr-Commit-Position: refs/heads/master@{#41531}

TBR=mstarzinger@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review-Url: https://codereview.chromium.org/2552893003
Cr-Commit-Position: refs/heads/master@{#41532}

src/compiler/pipeline.cc

@@ -1762,15 +1762,10 @@ bool PipelineImpl::ScheduleAndSelectInstructions(Linkage* linkage,
         info(), data->graph(), data->schedule()));
   }
 
-  // TODO(ishell): Always enable graph verification of stubs in debug mode
-  // once all the issues are fixed.
-  bool verify_stub_graph =
-      DEBUG_BOOL && FLAG_csa_verify && data->info()->IsStub();
-
-  if (verify_stub_graph || (FLAG_turbo_verify_machine_graph != nullptr &&
+  if (FLAG_turbo_verify_machine_graph != nullptr &&
       (!strcmp(FLAG_turbo_verify_machine_graph, "*") ||
        !strcmp(FLAG_turbo_verify_machine_graph,
-                                     data->info()->GetDebugName().get())))) {
+               data->info()->GetDebugName().get()))) {
     Zone temp_zone(data->isolate()->allocator(), ZONE_NAME);
     MachineGraphVerifier::Run(data->graph(), data->schedule(), linkage,
                               &temp_zone);

src/flag-definitions.h

@@ -444,7 +444,6 @@ DEFINE_BOOL(turbo_asm_deoptimization, false,
 DEFINE_BOOL(turbo_verify, DEBUG_BOOL, "verify TurboFan graphs at each phase")
 DEFINE_STRING(turbo_verify_machine_graph, nullptr,
               "verify TurboFan machine graph before instruction selection")
-DEFINE_BOOL(csa_verify, false, "verify TurboFan machine graph of code stubs")
 DEFINE_BOOL(turbo_stats, false, "print TurboFan statistics")
 DEFINE_BOOL(turbo_stats_nvp, false,
             "print TurboFan statistics in machine-readable format")

test/cctest/test-code-stub-assembler.cc

@@ -1927,44 +1927,5 @@ TEST(BuildAppendJSArrayFastDoubleElementsObject) {
       isolate->heap()->undefined_value(), Smi::FromInt(6), 6, 4);
 }
 
-TEST(CodeStubAssemblerGraphsCorrectness) {
-  // The test does not work with interpreter because bytecode handlers taken
-  // from the snapshot already refer to precompiled stubs from the snapshot
-  // and there is no way to trigger bytecode handlers recompilation.
-  if (i::FLAG_ignition || i::FLAG_turbo) return;
-
-  i::FLAG_csa_verify = true;
-
-  v8::Isolate::CreateParams create_params;
-  create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
-  v8::Isolate* isolate = v8::Isolate::New(create_params);
-  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-
-  {
-    v8::Isolate::Scope isolate_scope(isolate);
-    LocalContext env(isolate);
-    v8::HandleScope scope(isolate);
-
-    {
-      // Enforce recompilation of the following stubs.
-      i::CodeStub::Major code_stub_keys[] = {
-          i::CodeStub::LoadIC,         i::CodeStub::LoadICTrampoline,
-          i::CodeStub::LoadGlobalIC,   i::CodeStub::LoadGlobalICTrampoline,
-          i::CodeStub::KeyedLoadICTF,  i::CodeStub::KeyedLoadICTrampolineTF,
-          i::CodeStub::StoreIC,        i::CodeStub::StoreICTrampoline,
-          i::CodeStub::KeyedStoreICTF, i::CodeStub::KeyedStoreICTrampolineTF,
-      };
-      i::Heap* heap = i_isolate->heap();
-      i::Handle<i::UnseededNumberDictionary> dict(heap->code_stubs());
-      for (size_t i = 0; i < arraysize(code_stub_keys); i++) {
-        dict = i::UnseededNumberDictionary::DeleteKey(dict, code_stub_keys[i]);
-      }
-      heap->SetRootCodeStubs(*dict);
-    }
-    // Generate some stubs here.
-  }
-  isolate->Dispose();
-}
-
 }  // namespace internal
 }  // namespace v8