Update src/doc/rustc-dev-guide/src/tests/directives.md

Co-authored-by: León Orell Valerian Liehr <[email protected]>

Author: pvdrz

src/doc/rustc-dev-guide/src/tests/directives.md

@@ -270,7 +270,7 @@ The `//@ edition` directive can take an exact edition, a bounded half-open range
 - A test with the `//@ edition: 2015..2021` directive can be run under both the 2015 and 2018 editions. However, CI will only run the test with the loweest edition possible (2015 in this case).
 - A test with the `//@ edition: 2018..` directive will run under any edition greater or equal than 2018. However, CI will only run the test with the lowest edition possible (2018 in this case).
 
-You can also force `./x test` to use a specific edition by passing the `-- --edition=` argument. However, tests with the `//@ edition` directive will only be run if the value of the `--edition` either matches the exact edition or is inside the edition range. For example, if we run `./x edition -- --edition=2015`:
+You can also force `./x test` to use a specific edition by passing the `-- --edition=` argument. However, tests with the `//@ edition` directive will only be run if the value of the `--edition` either matches the exact edition or is inside the edition range. For example, if we run `./x test -- --edition=2015`:
 
 - A test with the `//@ edition: 2018` will not be run. 
 - A test with the `//@ edition: 2015..2021` will be run.