Summary: Remove explicit GC flags in regression tests
Reviewed-by: never, ysr

6877254: Server vm crashes with no branches off of store slice" when run with CMS and UseSuperWord(default)
Summary: design StoreCMNode::Ideal to promote its oopStore input if the input is a MergeMem node
Reviewed-by: kvn, never

Reviewed-by: kvn

Summary: The CR's test crashes with SIGSEGV when running with "-server -Xcomp" using using 32bit jvm.
Reviewed-by: kvn, never, rasbold

Summary: The C2 compiler leads to wrong results on solaris-i486 (32-bit) for a testcase given in the CR.
Reviewed-by: never, rasbold

Reviewed-by: kvn, jrose