[stubs] Add FLAG_enable_slow_asserts check to CSA_SLOW_ASSERT

src/code-stub-assembler.h

 // Copyright 2016 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.
 
 #ifndef V8_CODE_STUB_ASSEMBLER_H_
 #define V8_CODE_STUB_ASSEMBLER_H_
 
 #include <functional>
 
 #include "src/compiler/code-assembler.h"
@@ skipping 1180 matching lines @@
                                      compiler::Node* length,
                                      compiler::Node* first,
                                      compiler::Node* second,
                                      AllocationFlags flags);
 
   static const int kElementLoopUnrollThreshold = 8;
 };
 
 #define CSA_ASSERT(x) Assert((x), #x, __FILE__, __LINE__)
 #ifdef ENABLE_SLOW_DCHECKS
-#define CSA_SLOW_ASSERT(x) Assert((x), #x, __FILE__, __LINE__)
+#define CSA_SLOW_ASSERT(x)               \
+  if (FLAG_enable_slow_asserts) {        \
+    Assert((x), #x, __FILE__, __LINE__); \
+  }
 #else
 #define CSA_SLOW_ASSERT(x)
 #endif
 
 DEFINE_OPERATORS_FOR_FLAGS(CodeStubAssembler::AllocationFlags);
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_CODE_STUB_ASSEMBLER_H_