[Rust] PrimitiveArray::new can create arrays not in spec

[asfimport]

Currently, PrimitiveArray::new passed with null_count != 0 creates an array that does not follow the specification, as it is initialized with a None null bitmap but a non-zero null_count.

This method also makes no attempt to check for the buffer's aligment, which leads to UB.

Since a change in this method's signature requires a backward incompatible change, and it is only used in tests, I propose that we just remove it: we have good offers to create primitive arrays:

• from an ArrayData,

• from a vector or vector of optionals

• from an iterator

  which covers all major cases.

Reporter: Jorge Leitão / @jorgecarleitao
Assignee: Jorge Leitão / @jorgecarleitao

PRs and other links:

• GitHub Pull Request #8560

_{Note: This issue was originally created as ARROW-10448. Please see the migration documentation for further details.}

[asfimport]

Neville Dipale / @nevi-me:
Issue resolved by pull request 8560
#8560