Ligatures have a maximum width

[Tyriar]

VS Code issue: microsoft/vscode#235988

With ligatures enabled:

With ligatures disabled:

[Tyriar]

This is caused by this condition since the texture size is hardcoded to 512:

xterm.js/src/browser/renderer/shared/TextureAtlas.ts

Lines 431 to 434 in 601efc3

	// Allow 1 cell width per character, with a minimum of 2 (CJK), plus some padding. This is used
	// to draw the glyph to the canvas as well as to restrict the bounding box search to ensure
	// giant ligatures (eg. =====>) don't impact overall performance.
	const allowedWidth = Math.min(this._config.deviceCellWidth * Math.max(chars.length, 2) + TMP_CANVAS_GLYPH_PADDING * 2, this._textureSize);

[Tyriar]

This is still an issue due to the maximum texture size being too small on common machines (macbooks).