Steps to reproduce (this PDF):
[page4.pdf](https://github.com/mozilla/pdf.js/files/5990272/page4.pdf)

````
npm install
node_modules/.bin/gulp dist-install
node examples/node/pdf2svg.js /tmp/page4.pdf
````

Error:
````
Error: Invalid SVG dimensions
    at unreachable (/tmp/pdf.js/build/dist/legacy/build/pdf.js:2086:9)
    at assert (/tmp/pdf.js/build/dist/legacy/build/pdf.js:2091:5)
    at DOMSVGFactory.create (/tmp/pdf.js/build/dist/legacy/build/pdf.js:640:24)
    at SVGGraphics._makeTilingPattern (/tmp/pdf.js/build/dist/legacy/build/pdf.js:24178:36)
    at SVGGraphics._makeColorN_Pattern (/tmp/pdf.js/build/dist/legacy/build/pdf.js:24127:23)
    at SVGGraphics.setFillColorN (/tmp/pdf.js/build/dist/legacy/build/pdf.js:24088:39)
    at SVGGraphics.executeOpTree (/tmp/pdf.js/build/dist/legacy/build/pdf.js:23634:22)
    at /tmp/pdf.js/build/dist/legacy/build/pdf.js:23508:18
    at process._tickCallback (internal/process/next_tick.js:68:7)
    at Function.Module.runMain (internal/modules/cjs/loader.js:834:11)
````
let crc = -1;
      for (let i = start; i < end; i++) {
        const a = (crc ^ data[i]) & 0xff;
        const b = crcTable[a];
        crc = (crc >>> 8) ^ b;
      }
      return crc ^ -1;
    }
    function writePngChunk(type, body, data, offset) {
      let p = offset;
      const len = body.length;
      data[p] = (len >> 24) & 0xff;
      data[p + 1] = (len >> 16) & 0xff;
      data[p + 2] = (len >> 8) & 0xff;
      data[p + 3] = len & 0xff;
      p += 4;
      data[p] = type.charCodeAt(0) & 0xff;
      data[p + 1] = type.charCodeAt(1) & 0xff;
      data[p + 2] = type.charCodeAt(2) & 0xff;
      data[p + 3] = type.charCodeAt(3) & 0xff;
      p += 4;
      data.set(body, p);
      p += body.length;
      const crc = crc32(data, offset + 4, p);
      data[p] = (crc >> 24) & 0xff;
      data[p + 1] = (crc >> 16) & 0xff;
      data[p + 2] = (crc >> 8) & 0xff;
      data[p + 3] = crc & 0xff;
    }
    function adler32(data, start, end) {