SVG before and after applying compound path in Illustrator for http://graphicdesign.stackexchange.com/questions/82491/how-to-convert-a-circle-to-a-path/82508

1. before.svg

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 612 157.41935">
  <defs>
    <style>
      .a {
        fill: #ed2024;
      }

      .b {
        fill: none;
        stroke: #ed2024;
        stroke-miterlimit: 10;
        stroke-width: 40px;
      }
    </style>
  </defs>
  <title>before</title>
  <rect class="a" width="100" height="100"/>
  <rect class="a" x="127.54853" width="100" height="100" rx="12" ry="12"/>
  <circle class="a" cx="305.09706" cy="50" r="50"/>
  <polygon class="a" points="482.646 50 457.646 93.301 407.646 93.301 382.646 50 407.646 6.699 457.646 6.699 482.646 50"/>
  <polygon class="a" points="560.194 12.169 592.212 0.8 591.278 34.721 612 61.615 579.405 71.209 560.194 99.2 540.983 71.209 508.388 61.615 529.111 34.721 528.176 0.8 560.194 12.169"/>
  <line class="b" y1="137.41935" x2="612" y2="137.41935"/>
</svg>

2. after.svg