Add TODO to look out for IMPALA-2208/PARQUET-251
Add TODO to look out for IMPALA-2208/PARQUET-251

When we implement reading page statistics, we will need to ignore some
corrupt statistics as described in these JIRAs.

Change-Id: I3134038fbb3765015f0339d8cd06e8438a9967f1
Reviewed-on: http://gerrit.cloudera.org:8080/651
Reviewed-by: Skye Wanderman-Milne <6d4b168ab637b0a20cc9dbf96abb2537f372f946@cloudera.com>
Tested-by: Internal Jenkins

ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC,ibmsoe/ImpalaPPC