add the ability to slice arrays

[usagi32]

Motivation

closes #28855

Changes

• Needed to change the grammar a little bit to be able to parse slice operators like rust i.e. arr[..], arr[1..=2] etc.
• Added Slice Expression that resolves to a normal array expression till const proprogation. The resulting array will be a copied subset of the original expression.

Maybe this could have been by adding references, range types and dynamically sized types, but for now, this should do.

Test Plan

• Added new tests.
• Rest should be taken care of by the CI.

[d0cd]

@usagi32 I like your approach to array slicing over my own! Specifically, that it is handled in constant propagation rather than code generation.

Would you be up for rebasing this PR onto this one: #28869?

[usagi32]

Sure

[usagi32]

@d0cd just did something. You can have a look.

[mohammadfawaz]

@d0cd just did something. You can have a look.

Is this now rebased on top onto #28869? If so, you may want to change the base branch and convert it to a draft until the #28869 is approved and merged.

[d0cd]

@usagi32 thanks for making the changes! I had to refresh feat/array-slicing so that the diff from this branch wasn't so large. Just a few conflicts left and we're good to go.

[usagi32]

@d0cd done