Add libslirp with glib shim

src/frontend/libslirp/CMakeLists.txt

@@ -0,0 +1,64 @@
+cmake_minimum_required(VERSION 3.16)
+
+project(libslirp VERSION 4.8.0 LANGUAGES C)
+
+set(SLIRP_MAJOR_VERSION "${libslirp_VERSION_MAJOR}")
+set(SLIRP_MINOR_VERSION "${libslirp_VERSION_MINOR}")
+set(SLIRP_MICRO_VERSION "${libslirp_VERSION_PATCH}")
+set(SLIRP_VERSION_STRING "\"${libslirp_VERSION}\"")
+
+set(SOURCES
+	src/arp_table.c
+	src/bootp.c
+	src/cksum.c
+	src/dhcpv6.c
+	src/dnssearch.c
+	src/if.c
+	src/ip6_icmp.c
+	src/ip6_input.c
+	src/ip6_output.c
+	src/ip_icmp.c
+	src/ip_input.c
+	src/ip_output.c
+	src/mbuf.c
+	src/misc.c
+	src/ncsi.c
+	src/ndp_table.c
+	src/sbuf.c
+	src/slirp.c
+	src/socket.c
+	src/state.c
+	src/stream.c
+	src/tcp_input.c
+	src/tcp_output.c
+	src/tcp_subr.c
+	src/tcp_timer.c
+	src/tftp.c
+	src/udp6.c
+	src/udp.c
+	src/util.c
+	src/version.c
+	src/vmstate.c
+
+	# glib shim
+	glib/glib.c
+)
+
+configure_file("${CMAKE_CURRENT_SOURCE_DIR}/src/libslirp-version.h.in" "${CMAKE_CURRENT_BINARY_DIR}/libslirp-version.h")
+
+add_library(slirp STATIC ${SOURCES})
+target_include_directories(slirp PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/glib")
+target_include_directories(slirp PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/src")
+target_include_directories(slirp PRIVATE "${CMAKE_CURRENT_BINARY_DIR}")
+
+target_compile_definitions(slirp PRIVATE BUILDING_LIBSLIRP)
+set_target_properties(slirp PROPERTIES INTERPROCEDURAL_OPTIMIZATION OFF)
+set_target_properties(slirp PROPERTIES INTERPROCEDURAL_OPTIMIZATION_RELEASE OFF)
+
+if (WIN32)
+	target_link_libraries(slirp PRIVATE ws2_32 iphlpapi)
+elseif(HAIKU)
+	target_Link_libraries(slirp PRIVATE network)
+elseif(APPLE)
+	target_link_libraries(slirp PRIVATE resolv)
+endif()