[CodeGen] Support arrays with initializers of 64-bit size

Based on @OfekShochat's https://reviews.llvm.org/D133648

init.c is the primary test for array initialization, but it uses a
32-bit triple, which would lead to an "array is too large" error. Add
the new test to array-init.c instead.

Fix #57353

Pull Request: https://github.com/llvm/llvm-project/pull/92473