Do not update the stack after it was freed by RETURN instruction

libevmjit/BasicBlock.cpp

@@ -137,6 +137,9 @@ void BasicBlock::synchronizeLocalStack(Stack& _evmStack)
 {
 	auto blockTerminator = m_llvmBB->getTerminator();
 	assert(blockTerminator != nullptr);
+	if (blockTerminator->getOpcode() != llvm::Instruction::Ret)
+	{
+		// Not needed in case of ret instruction. Ret also invalidates the stack.
 		m_builder.SetInsertPoint(blockTerminator);
 
 		auto currIter = m_currentStack.begin();
@@ -164,6 +167,7 @@ void BasicBlock::synchronizeLocalStack(Stack& _evmStack)
 			assert(*currIter != nullptr);
 			_evmStack.push(*currIter);
 		}
+	}
 
 	// Emit get() for all (used) values from the initial stack
 	for (size_t idx = 0; idx < m_initialStack.size(); ++idx)