bug: strange compiler behavior: tiny change => nonsense error in other place

I've encountered some strange things in the compiler lately. It turns out it's not SDK version related (at least it happens also in SDK 8.4.0, 8.3.0, 8.2.3, 8.1.1). I think it is somehow related to project size and optimization (maybe just how the compiler works).

What happens is that I do a tiny little change somewhere in my code, and then a totally nonsense error pops up in a different place. I have now an example (though it's just to demonstrate the issue, I don't think anyone will be able to reproduce this without my project) where this happens within a file. This is the file:

import Toybox.Graphics;
import Toybox.Lang;

/* 
 * 205 x 148 SQUARE FONT GROUP A
 * DEVICES:
 * - vivoactive
 */

const LAYOUT_LINE1 = 15;
const LAYOUT_LINE2 = 42;
const LAYOUT_LINE3 = 95;
const LAYOUT_LINE4 = 120;
const LAYOUT_stepGoalProgressOffsetX = 0;
const LAYOUT_stepGoalProgressHeight = 3;
const LAYOUT_centerOffsetX = 4;
const LAYOUT_clockY = 5;
const LAYOUT_clockOffsetX = 0;
const LAYOUT_topRowY = LAYOUT_LINE1 + 12;
const LAYOUT_middleRowOffsetX = 5;
const LAYOUT_middleRowLabelY = LAYOUT_LINE2 + 8;
const LAYOUT_middleRowValueY = LAYOUT_LINE2 + 8 + 25;

// line with small change
const LAYOUT_heartRateIconY = LAYOUT_LINE3 - 20;

const LAYOUT_heartRateIconHRZY = 107;
const LAYOUT_heartRateIconWidth = 20;
const LAYOUT_heartRateIconHRZWidth = 28;
const LAYOUT_heartRateIconXOffset = 2;
const LAYOUT_heartRateIconHRZXOffset = 2;
const LAYOUT_heartRateTextY = LAYOUT_middleRowLabelY;
const LAYOUT_bottomRowUpperTextY = 160;
const LAYOUT_bottomRowLowerTextY = 185;
const LAYOUT_bottomRowIconX = 4;
const LAYOUT_bottomRowIconY = 155;
const LAYOUT_batteryY = 222;
const LAYOUT_batteryX = 0;
const LAYOUT_batteryWidth = 49;
const LAYOUT_batteryHeight = 22;
const LAYOUT_timeFont = Graphics.FONT_XTINY;
const LAYOUT_topRowFont = Graphics.FONT_MEDIUM;
const LAYOUT_heartRateFont = Graphics.FONT_MEDIUM;
const LAYOUT_middleRowLabelFont = Graphics.FONT_XTINY;
const LAYOUT_middleRowValueFontShrunk = Graphics.FONT_LARGE;
const LAYOUT_middleRowValueFont = Graphics.FONT_NUMBER_MEDIUM;
const LAYOUT_bottomRowFont = Graphics.FONT_MEDIUM;

// line with error
const LAYOUT_batteryFont = Graphics.FONT_XTINY;

const LAYOUT_eightColourPalette = false;
const LAYOUT_GPS_ICON_X = 58;
const LAYOUT_GPS_ICON_Y = 211;
const LAYOUT_WIDTH = 205;

If the line is:

const LAYOUT_heartRateIconY = LAYOUT_LINE3;