UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36

Steps to reproduce the problem:
vec2 V = U/iResolution.xy, W = mat2(V,-V.y,V.x)*V;  
does not compile while
vec2 V = U/iResolution.xy, W = mat2(V.x,V.y,-V.y,V.x)*V; compiles.

(in all other circumstances, using V.xy for V.x,V.y in constructors does work fine).

acid test here: https://www.shadertoy.com/view/MlyXW1

What is the expected behavior?
compiling.

What went wrong?
not compiling.

Did this work before? No 

Chrome version: 58.0.3029.81  Channel: stable
OS Version: 14.04
Flash Version: Shockwave Flash 25.0 r0

issue on chrome+chromium but not on firefox (on linux and windows).