Fix error messages; tensor creation method names with type (#26219)
Summary:
After offline discussion with dzhulgakov :
- In future we will introduce creation of byte signed and byte unsigned dtype tensors, but java has only signed byte - we will have to add some separation for it in method names ( java types and tensor types can not be clearly mapped) => Returning type in method names
- fixes in error messages
- non-static method Tensor.numel()
- Change Tensor toString() to be more consistent with python
Update on Sep 16:
Type renaming on java side to uint8, int8, int32, float32, int64, float64
```
public abstract class Tensor {
public static final int DTYPE_UINT8 = 1;
public static final int DTYPE_INT8 = 2;
public static final int DTYPE_INT32 = 3;
public static final int DTYPE_FLOAT32 = 4;
public static final int DTYPE_INT64 = 5;
public static final int DTYPE_FLOAT64 = 6;
```
```
public static Tensor newUInt8Tensor(long[] shape, byte[] data)
public static Tensor newInt8Tensor(long[] shape, byte[] data)
public static Tensor newInt32Tensor(long[] shape, int[] data)
public static Tensor newFloat32Tensor(long[] shape, float[] data)
public static Tensor newInt64Tensor(long[] shape, long[] data)
public static Tensor newFloat64Tensor(long[] shape, double[] data)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26219
Differential Revision: D17406467
Pulled By: IvanKobzarev
fbshipit-source-id: a0d7d44dc8ce8a562da1a18bd873db762975b184
