Reproduction steps:
1) Open user's attached project (for easier reproduction don't change layout)
2) Open "Shadow Glitch" scene
3) Open Game view

Expected result:
Shadows casted from Line Renderer should be rendered the same way as they would have been casted from simple meshes

Actual result:
Shadows are rendered very randomly (sometimes they are 1/5 of lines length, sometimes they are invisible, sometimes rendered on half of a shadow receiver (as shown in "bug.png"))

Note:
Bug can be reproduced also when changing "Line Renderer" objects position and rotation. Also camera's rotation affects this too.

Note 2:
Bug always reproduces when one of "Line Renderer"s is not visible for camera. Also I was unable to reproduce this in Scene view

Regression happened from 5.3.4p2