[stubs] Enable machine graph verification for CodeStubAssembler and friends by default in debug mode

src/fast-accessor-assembler.cc

Index: src/fast-accessor-assembler.cc
diff --git a/src/fast-accessor-assembler.cc b/src/fast-accessor-assembler.cc
index fbec6d6fc33e69b47b217dbc4780d7b93b2e20e7..a1bd12d3b8d249d5ce56623505887c3eb5124717 100644
--- a/src/fast-accessor-assembler.cc
+++ b/src/fast-accessor-assembler.cc
@@ -240,8 +240,8 @@ void FastAccessorAssembler::CheckIsJSObjectOrJump(ValueId value_id,
 
 MaybeHandle<Code> FastAccessorAssembler::Build() {
   CHECK_EQ(kBuilding, state_);
-  Handle<Code> code = compiler::CodeAssembler::GenerateCode(
-      assembler_state_.get(), FLAG_csa_verify);
+  Handle<Code> code =
+      compiler::CodeAssembler::GenerateCode(assembler_state_.get());
   state_ = !code.is_null() ? kBuilt : kError;
   Clear();
   return code;