Fix build for macOS where endian.h is not available

[cho-m]

It is possible other platforms were impacted as the header/functions aren't that portable.

Specific errors:

common/network/NetworkUtils.cpp:166:2: error: "No be64toh for NetworkToHost, please report this."
  166 | #error "No be64toh for NetworkToHost, please report this."
      |  ^
common/network/NetworkUtils.cpp:182:2: error: "No be64toh for NetworkToHost, please report this."
  182 | #error "No be64toh for NetworkToHost, please report this."
      |  ^
common/network/NetworkUtils.cpp:206:2: error: "No htobe64 for HostToNetwork, please report this."
  206 | #error "No htobe64 for HostToNetwork, please report this."
      |  ^
common/network/NetworkUtils.cpp:214:2: error: "No htobe64 for HostToNetwork, please report this."
  214 | #error "No htobe64 for HostToNetwork, please report this."
      |  ^
4 errors generated.

[peternewman]

Thanks for this @cho-m and sorry for breaking things for you.

Rather than redefining be64toh and htobe64, we prefer to do ifdefs to handle the different cases. We should probably also add a header check for libkern/OSByteOrder.h and use that rather than APPLE to switch the behaviour.

[peternewman]

So remove this:

Suggested change

	#define be64toh(x) OSSwapBigToHostInt64(x)
	#define htobe64(x) OSSwapHostToBigInt64(x)

[peternewman]

Switch this to including OSByteOrder.h if its present.

[peternewman]

Then switch this, and the following cases, to something more like

ola/common/network/NetworkUtils.cpp

Lines 684 to 712 in e8c755c

	#ifdef USE_SYSCTL_FOR_DEFAULT_ROUTE
	return GetDefaultRouteWithSysctl(if_index, default_gateway);
	#elif defined(USE_NETLINK_FOR_DEFAULT_ROUTE)
	return GetDefaultRouteWithNetlink(if_index, default_gateway);
	#elif defined(_WIN32)
	ULONG size = 4096;
	PMIB_IPFORWARDTABLE forward_table =
	reinterpret_cast<PMIB_IPFORWARDTABLE>(malloc(size));
	DWORD result = GetIpForwardTable(forward_table, &size, TRUE);
	if (result == NO_ERROR) {
	for (unsigned int i = 0; i < forward_table->dwNumEntries; ++i) {
	if (forward_table->table[i].dwForwardDest == 0) {
	*default_gateway =
	IPV4Address(forward_table->table[i].dwForwardNextHop);
	*if_index = forward_table->table[i].dwForwardIfIndex;
	}
	}
	free(forward_table);
	return true;
	} else {
	OLA_WARN << "GetIpForwardTable failed with " << GetLastError();
	return false;
	}
	#else
	#error "DefaultRoute not implemented for this platform, please report this."
	// TODO(Peter): Do something else on machines without Netlink
	// No Netlink, can't do anything
	return false;
	#endif // USE_SYSCTL_FOR_DEFAULT_ROUTE

(but I don't think we need the extra wrapper functions here).