* fixes masking error in tx8664shlshrnode.pass_generate_code
* cleaned up tx8664shlshrnode.pass_generate_code and fix register loading of the right node, resolves #25664

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@26716 3ad0048d-3df7-0310-abae-a5850022a9f2