public static Address getThunkedAddr(Program program, Address entry) {
		return getThunkedAddr(program, entry, true);
	}
if the code starting at entry is a thunk, return the thunked addess if known.

@param program code resides in
@param entry start of the code
@return the function address, Address.NO_ADDRESS if thunk but unknonw addr, null otherwise
Ghidra/Features/Base/src/main/java/ghidra/app/cmd/function/CreateThunkFunctionCmd.java