SystemC simulation failure when initailizing ILA memory state with BvConst

[LeeOHzzZ]

Describe the bug
SystemC compilation error happens when initializing the ILA memory state with BvConst

To Reproduce
Steps to reproduce the behavior:

1. declare a memstate in ILA
2. initialize the memstate with BvConst: instr.SetUpdate(memstate, Store(memstate, addr, BvConst(0, addr_width))
3. compile the generated systemc code, can you will encounter error such as " memstate_sc[addr] = 0.to_int()", a constant in systemc doesn't have to_int() function.

Environment (please complete the following information):

• OS: [e.g. Ubuntu 18.04]
• Compiler [e.g. gcc 7.3.0, clang 6.0.0]
• Other dependencies [e.g. z3 4.4.1, boost 1.65.0]