Upcast/downcast old ExclusiveMin/Max

[darrelmiller]

Upcast from 2/3 to 3.1

If ExclusiveMin/Max is true
Copy Min/Max value to ExclusiveMin/Max value and remove Min/Max keyword

if ExclusiveMin/Max is false
do nothing

Downcast from 3.1 to earlier

if ExclusiveMin/Max has non-null value
Write ExclusiveMin/Max as true and write min/max value