[bun:ffi] Implement `read.{u8,i8,i16,i32,u16,u32,ptr,intptr}`

`read` in `bun:ffi` lets you read data from a pointer without creating a new DataView/ArrayBufferView

```
import {read} from 'bun:ffi';

    expect(read.i8(ptr_, i)).toBe(view.getInt8(i, true));
    expect(read.i16(ptr_, i)).toBe(view.getInt16(i, true));
    expect(read.i32(ptr_, i)).toBe(view.getInt32(i, true));
    expect(read.u8(ptr_, i)).toBe(view.getUint8(i, true));
    expect(read.u16(ptr_, i)).toBe(view.getUint16(i, true));
    expect(read.u32(ptr_, i)).toBe(view.getUint32(i, true));
  }
```