message: fix dynamic lighting frozen calculation
  this broke recently with the reverse-z, the froxel calculation relies
  on the depth, which is now inverted.
  we actually fix our getNormalizedViewportCorrd() public API, which the
  froxel code uses.
diff: @@ -89,11 +89,13 @@ highp vec3 getLightSpacePosition() {
  /**
  * Returns the normalized [0, 1] viewport coordinates with the origin at the viewport's bottom-left.
  + * Z coordinate is in the [0, 1] range as well.
  *
  * @public-api
  */
  highp vec3 getNormalizedViewportCoord() {
  - return vec3(shading_normalizedViewportCoord, gl_FragCoord.z);
  + // make sure handle our reversed-z
  + return vec3(shading_normalizedViewportCoord, 1.0 - gl_FragCoord.z);
  }
  #if defined(HAS_SHADOWING) && defined(HAS_DYNAMIC_LIGHTING)
  