rust/tests/rustdoc-ui/invalid-theme-name.rs

//@ compile-flags:--theme {{src-base}}/invalid-theme-name.rs
//@ error-pattern: invalid argument
//@ error-pattern: must have a .css extension
Give a better error when --theme is not a CSS file Before: ``` error: invalid argument: "bacon.toml" ``` After: ``` error: invalid argument: "bacon.toml" \| = help: arguments to --theme must be CSS files ``` 2021-03-31 09:27:01 -05:00			`//@ compile-flags:--theme {{src-base}}/invalid-theme-name.rs`
			`//@ error-pattern: invalid argument`
			`//@ error-pattern: must have a .css extension`