[SOLVED] 352.09: bug in shader compiler? exposed by X-Plane 10.35

X-Plane 10.35 crashes when it loads various assets, doesn’t happen with 349.* drivers.

Resources/shaders/terrain_frag.glsl: 0(304) : error C1008: undefined variable “STEPS”
0(310) : error C1008: undefined variable “STEPSI”
0(318) : error C1008: undefined variable “STEPS”
Resources/shaders/terrain_vert.glsl+Resources/shaders/terrain_frag.glsl: Fragment info

0(304) : error C1008: undefined variable “STEPS”
0(310) : error C1008: undefined variable “STEPSI”
0(318) : error C1008: undefined variable “STEPS”

EDIT: the X-Plane guys added a workaround.