Fix #1226: Store minimal info in IR to construct hierarchy
Remove old deserialization hack
Fix #1374: IntType, FloatType and DoubleType should not be exact.
Fix #1297: Make 0.0.equals(-0.0) be false.
Merge pull request #1366 from gzm0/simplify-ancestor-info

Fix #1226: Store minimal info in IR to construct hierarchy
Merge pull request #1373 from sjrd/minus-zero

Fix #1297: Make 0.0.equals(-0.0) be false.