Identify the Bug

Fixes #21093
Fixes #20884
Fixes #20897
Fixes atom/language-javascript#676

1. The Rust grammar had a bug that caused poor error recovery.

2. There was a bug would occur in documents with language injections, where the injected document is empty. Examples include:

   • An empty string assigned to a node's innerHTML property in JavaScript. Usually, we highlight the contents of these strings as HTML.

     node.innerHTML = "";

   • An empty script tag in an HTML document. Usually, we would parse the tag's contents this script tag as JavaScript:

     <div>
       <script></script>
     </div>

   • In Ruby or JavaScript, a regular expression literal whose entire contents consist of escape sequences. Usually we highlight the contents of the regular expression using regex syntax:

     s.search /\n/

The bug would cause us to accidentally skip highlighting large sections of the document.

Description of the Change

These injected syntax trees are each associated with a Marker in the LanguageMode's injectionsMarkerLayer. This PR ensures that, when a language injection is empty, its marker is destroyed.

I also upgraded to the latest version of tree-sitter-rust in order to fix the last two issues mentioned in #21093, which were. unrelated, but easy to address.

Verification Process

Create files containing all of the code examples in #21093. See that the syntax highlighting is all correct. Edit this files in a variety of ways and see that syntax highlighting stays correct.

Release Notes

Fixed a syntax highlighting bug that caused inconsistent and missing highlighting in several languages.