[clang] [CIR] Upstream basic support for ArrayType (PR #130502)

[Amr Hesham via cfe-commits]

AmrDeveloper wrote:

There will be two upcoming patches.

1 - Initializing const array and zero initializing support (Depends on upstreaming `ConstantEmitter` and `ZeroAttr`)
2 - Dynamic-size arrays, and accessing arrays using the `cir.ptr_stride` operation (Depends on upstreaming `CastOp`)


https://github.com/llvm/llvm-project/pull/130502