Ditz issue update
Bug testcase for Date time value edge case bugs

Two test262 cases failed.  The tests use Date constructor to create timestamps
near the Ecmascript valid range edge.  The Date constructor operates with local
time values, which caused some previous sanity checks to trigger: temporary
time values which have a local tzoffset can be just outside the valid Ecmascript
range which trigger some invalid behavior and one assert failure.
Fix Date corner case bugs, tzoffset/local time

Tzoffset calculations would be skipped if a temporary time value was just
outside the Ecmascript range.  This can happen in some legitimate cases,
so a +/- 24h leeway was added to the check.  This fixes a few test262
cases documented in test-bug-date-timeval-edges.js.

Similarly, add a +/- 24h leeway for an assert in local-time-to-parts
conversion.  When converting a time value to parts and the parts are
requested in local time, a temporary time value (simulating local time) can
be just outside the Ecmascript range.  Allow +/- 24h leeway in the assert
to avoid triggering it in valid edge cases.

See test-bug-date-timeval-edges.js for demonstration of both issues.
Merge branch 'date-timeval-edge-fix'

Fix a few edge cases related to local time handling near the valid Ecmascript
time value limits.  Two test262 test cases failed due to recently added sanity
checks (which were necessary to avoid integer overflows in extreme cases), and
one assert was broken.

There's no need for a release note because this merge fixes issues introduced
by other changes in the release.
Ditz issue update