syntax highlighting error in arithmetic expressions

[alexr00]

The code with a problem is:

z=$((x + y))

x is yellow entity.name.command.shell

• y is brown string.unquoted.argument.shell

It looks like:

It should look like:

I would expect x and y to have the same scopes.

Originally from @mcandre in https://github.com/microsoft/vscode/issues/231217#issuecomment-2410800447

[LeoH1310]

The following problem may be related to this. When using arithmetic shift operation, everything after it is highlighted as a string. Like this: z=$((x << y))