Improper handling of `//` and `/*` in unknown at rules in SCSS

// should not mark a comment here:

This compiles fine but displays an error in VS Code. Though if there were a space, for example, before the //, then it should mark a comment and throw an error.

Another example is that VS Code does not display a syntax error for this despite it throwing an error during compilation:

All of this also applies to /*. This should not be a comment:

CSS has none of these issues, while SCSS does.

Additionally, it may be worth noting that the syntax highlighting is fixed when an @each rule precedes the unknown at rule, but the parsing is still incorrect as it still shows an error despite the syntax being fine. (Not every at rule fixes the syntax highlighting, and @each is the only such one I found from my testing.)

Reproduce the reported SCSS cases involving unknown at-rules and // or /*, including the @each example, and compare syntax highlighting with compilation errors. Trace the SCSS parsing and highlighting entry points, then verify that comments, parsing, diagnostics, and highlighting consistently match the described behavior.