New Render Textures appear with visual artefacts in the Project/Inspector previews in OSX editor.

Repro steps:
1. Open attached project or create a new project.
2. Right click in the project folder and create new render texture.
3. Observe that the new texture does not appear blank.

Expected outcome: new render textures to appear blank/black when created.

Notes:
- not a regression, occurs as far back as 5.2.3f1 (f3d16a1fa2dd)
- reproducible also on Windows 10 x64, Intel HD 4600, DX11, but not on GTX 960m (v. 5.4b8)
- creating new textures seems to change the pattern (gif attached)
- textures seem to work fine, it just doesn't look very polished/professional