gcc-final: install libatomic

It's required in some 32-bit architectures for the extended (64-bit)
atomic operations, like __sync_add_and_fetch_8.
These arches are at least: i386, mips & mipsel.

Target size growth is ~15 KiB for ARM.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/gcc/gcc-final/gcc-final.mk

@@ -118,6 +118,15 @@ endef
 
 HOST_GCC_FINAL_POST_INSTALL_HOOKS += HOST_GCC_FINAL_INSTALL_LIBGCC
 
+define HOST_GCC_FINAL_INSTALL_LIBATOMIC
+	-cp -dpf $(HOST_DIR)/usr/$(GNU_TARGET_NAME)/lib*/libatomic* \
+		$(STAGING_DIR)/lib/
+	-cp -dpf $(HOST_DIR)/usr/$(GNU_TARGET_NAME)/lib*/libatomic* \
+		$(TARGET_DIR)/lib/
+endef
+
+HOST_GCC_FINAL_POST_INSTALL_HOOKS += HOST_GCC_FINAL_INSTALL_LIBATOMIC
+
 # Handle the installation of libraries in /usr/lib
 HOST_GCC_FINAL_USR_LIBS =