Tailwind 3.1 regression: No longer keeps classes mentioned in markdown backticks

[LeoniePhiline]

What version of Tailwind CSS are you using?

For example: v3.1.0

What build tool (or framework if it abstracts the build tool) are you using?

• parcel
• tailwindcss play

What version of Node.js are you using?

For example: v16.14.2

What browser are you using?

For example: Firefox

What operating system are you using?

For example: OpenSUSE linux

Reproduction URL

https://play.tailwindcss.com/XRYewVE3SL

Describe your issue

Check Generated CSS -> Components.

The classes .alert-success .alert-info .alert-failure are missing in TailwindCSS 3.1, but are rendered in TailwindCSS 3.0 and earlier. This is a 3.1.0 regression.

Removing the backticks around the class names (but keeping the leading .) in the HTML comment makes the classes get rendered in TailwindCSS 3.1 as well.

Note

This might have the same root cause as #8557 has.