[Matrix] Implement matrix support for the `fwidth` HLSL Function

> Note: This issue tracks matrix support for `fwidth`. The original implementation issue is [here](https://github.com/llvm/llvm-project/issues/99120).

Matrix requirements:
- [ ] https://github.com/llvm/wg-hlsl/issues/387

## HLSL:

Returns the absolute value of the partial derivatives of the specified value.

| *ret* fwidth(*x*) |
|-------------------|

This function computes the following: [**abs**](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src//direct3dhlsl/dx-graphics-hlsl-abs.md)([**ddx**](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src//direct3dhlsl/dx-graphics-hlsl-ddx.md)(*x*)) + [**abs**](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src//direct3dhlsl/dx-graphics-hlsl-abs.md)([**ddy**](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src//direct3dhlsl/dx-graphics-hlsl-ddy.md)(*x*)).

This function is only supported in pixel shaders.

## Parameters

| Item | Description |
|--------------------------------------------------------|----------------------------------------|
| *x*
| \[in\] The specified value.
|

## Return Value

The absolute value of the partial derivatives of the *x* parameter.

## Type Description

| Name | [**Template Type**](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src//direct3dhlsl/dx-graphics-hlsl-intrinsic-functions.md) | [**Component Type**](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src//direct3dhlsl/dx-graphics-hlsl-intrinsic-functions.md) | Size |
|-------|----------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------|--------------------------------|
| *x* | [**scalar**](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src//direct3dhlsl/dx-graphics-hlsl-intrinsic-functions.md), **vector**, or **matrix** | [**float**](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src/WinProg/windows-data-types.md) | any |
| *ret* | same as input *x* | [**float**](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src/WinProg/windows-data-types.md) | same dimension(s) as input *x* |

## Minimum Shader Model

This function is supported in the following shader models.

| Shader Model | Supported |
|------------------------------------------------------------------------------------|---------------------|
| [Shader Model 3 (DirectX HLSL)](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src//direct3dhlsl/dx-graphics-hlsl-sm3.md) and higher shader models | yes |
| [Shader Model 2 (DirectX HLSL)](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src//direct3dhlsl/dx-graphics-hlsl-sm2.md) | yes (ps\_2\_x only) |
| [Shader Model 1 (DirectX HLSL)](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src//direct3dhlsl/dx-graphics-hlsl-sm1.md) | no |

## See also

[**Intrinsic Functions (DirectX HLSL)**](https://github.com/MicrosoftDocs/win32/blob/docs/desktop-src//direct3dhlsl/dx-graphics-hlsl-intrinsic-functions.md)