This GLSL function was only added in 1.40, and thus should never be exposed in lower versions.
Good catch, thanks! I apparently screwed this up in 722eff674b832e2321f791c68358ef52d2a1ff25.
I just mailed out a patch:
Fixed in master by:
Author: Kenneth Graunke <email@example.com>
Date: Wed Dec 16 00:56:39 2015 -0800
glsl: Remove inverse() from GLSL 1.20 and 1.30.
I apparently regressed this when rewriting the built-ins using
ir_builder, in 76d2f73643f.
Signed-off-by: Kenneth Graunke <firstname.lastname@example.org>
Reviewed-by: Ilia Mirkin <email@example.com>
Reviewed-by: Matt Turner <firstname.lastname@example.org>