RFR (XS): 8220345: Use appropriate type for G1RemSetScanState::IsDirtyRegionState

[Thomas Schatzl]

Hi all,

  can I have reviews for this small change that removes the use of
jbyte for an internal data type in favor of the initially intended bool
?

The original reason to do so was "G1RemSetScanState::IsDirtyRegionState
is a jbyte because "since there are no atomic instructions for
bools".", but this is obviously no longer true, and the workaround can
be removed.

CR:
https://bugs.openjdk.java.net/browse/JDK-8220345
Webrev:
http://cr.openjdk.java.net/~tschatzl/8220345/webrev/
Testing:
hs-tier1-5

Thanks,
  Thomas