Expect an array when expected and acutal types are both arrays during cast

[xizheyin]

Closing #138836

[rustbot]

r? @fee1-dead

rustbot has assigned @fee1-dead.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[compiler-errors]

Please write a description for why this code fixes the issue and especially why it's not going to affect existing code.

My first reaction to this code is definitely not the right way to fix a diagnostics issue, since it is code that is exercised even when there are no failures.

[compiler-errors]

@rustbot author

[xizheyin]

This is the handling of special circumstances. But I missed one condition.

This function checks when cast &m_expr as *const m_cast.

If the type m_expr is [ty1; N] and the type m_cast is [ty2; M], where M!=N, and ty1 is not [ty2; M], we need to use [ty1; N] instead of ty1 as the expected type.

The example is shown in the corresponding issue and the ui test newly added.

In this case, the code before and after modification will definitely report an error, so it will not affect the original logic. @compiler-errors