BuildSystem: add rule to build libstdc++

We can now build libstdc++ and actually link with g++

CMakeLists.txt

@@ -54,6 +54,12 @@ add_custom_target(toolchain
 	USES_TERMINAL
 )
 
+add_custom_target(libstdc++
+	COMMAND ${CMAKE_COMMAND} -E env LIBSTDCPP="1" ${CMAKE_SOURCE_DIR}/toolchain/build.sh
+	DEPENDS libc-install
+	USES_TERMINAL
+)
+
 add_custom_target(image
 	COMMAND ${CMAKE_COMMAND} -E env SYSROOT="${BANAN_SYSROOT}" DISK_IMAGE_PATH="${DISK_IMAGE_PATH}" ${CMAKE_SOURCE_DIR}/image.sh
 	DEPENDS kernel-install

toolchain/build.sh

@@ -6,6 +6,13 @@ GCC_VERSION="gcc-12.2.0"
 
 cd $(dirname "$0")
 
+if [[ -n $LIBSTDCPP ]]; then
+	cd build/${GCC_VERSION}/
+	make -j $(nproc) all-target-libstdc++-v3
+	make install-target-libstdc++-v3
+	exit 0
+fi
+
 if [[ -z $SYSROOT ]]; then
 	echo "You must set the SYSROOT environment variable" >&2
 	exit 1

userspace/CMakeLists.txt

@@ -17,7 +17,6 @@ add_custom_target(userspace)
 add_custom_target(userspace-install DEPENDS userspace)
 
 foreach(USERSPACE_PROJECT ${USERSPACE_PROJECTS})
-	target_link_options(${USERSPACE_PROJECT} PUBLIC -nodefaultlibs)
 	add_dependencies(userspace ${USERSPACE_PROJECT})
 	add_dependencies(userspace-install ${USERSPACE_PROJECT}-install)
 endforeach()