nopackages: Add class for recipes which don't generate packages

It turns out writing the same list of packaging tasks multiple
times in multiple places is error prone. Move this to a new class
'nopackages", migrate existing users and add glibc-initial and
libgcc-initial since we don't want packages for those recipes.

This means the sstate for those recipes won't be installed, saving
small amounts of build time and bandwidth.

A reference to the old package_write task is also dropped.

(From OE-Core rev: cece583d58f82a50c3a4eac876eb326ac3b8f5e5)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/native.bbclass

@@ -169,13 +169,7 @@ python native_virtclass_handler () {
 addhandler native_virtclass_handler
 native_virtclass_handler[eventmask] = "bb.event.RecipePreFinalise"
 
-deltask package
-deltask packagedata
-deltask package_qa
-deltask package_write_ipk
-deltask package_write_deb
-deltask package_write_rpm
-deltask package_write
+inherit nopackages
 
 do_packagedata[stamp-extra-info] = ""
 do_populate_sysroot[stamp-extra-info] = ""