Bug in Metal when gl_FragDepth is used but not written to by a shader
causing depth-based navigation to fail. Patch ensures gl_FragDepth
is assigned a default value at the current depth from the vertex
shader to catch all edge-cases of this.
Authored by Apple: Michael Parkin-White
Co-authored-by: Michael Parkin-White <mparkinwhite@apple.com>
Pull Request: https://projects.blender.org/blender/blender/pulls/108453
91e15ca2fa