gcc: Ensure that the shared source directory shared the same sstate hashes
The fetch/unpack/patch/headerfix tasks are shared and hence their sstate hashes
should also match. Sadly this is not the case since:
a) gcc-runtime applies an additional patch
b) The do_headerfix task was missing from libgcc
c) The do_headerfix task is a shell task and hence depends
on all exported variables which can vary between cross and target
recipes.
To fix this, the patch moves the patch to the common code, adds
the headerfix task to a common include file and disabled shell
dependencies on the do_headerfix task since its clear in this case
we don't need thsoe dependencies since we just call sed.
With this patch applied, all these recipes now share common sstate checksums.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
