[clang] [clang] Fix direct-initialization with new expressions for arrays (PR #78201)

[Alan Zhao via cfe-commits]

alanzhao1 wrote:

> I believe the approach here is not sufficient and we have a current PR in progress: #76976
> 
> we also need codegen work to implement this.

Correct - here are some examples that will cause this to fail:

```cpp
void foo(int n) {
  new int[n](1, 2);
}
```

```cpp
void bar() {
  new char[]("abcd");
}
```


https://github.com/llvm/llvm-project/pull/78201