8000805: JMM issue: short loads are non-atomic Summary: perform transforms during IGVN phase when Load has a single user. Reviewed-by: jrose, kvn, twisti

8001101: C2: more general vector rule subsetting Summary: Allow which vector rules are supported to be decided at runtime. Also a small change to allow vector types in Type::_type_info[] to apply to more platforms. Reviewed-by: kvn, twisti Contributed-by: dean.long@oracle.com