test(ui/lint): demonstrate the current cmdline lint behavior

This demonstrates the current behavior of adding lint form the command
line. generally the lint levels are ignored as the current implementation
unconditionally emit errors for those lints.

tests/ui/lint/lint-removed-cmdline-deny.rs

@@ -0,0 +1,12 @@
+// The raw_pointer_derived lint warns about its removal
+// cc #30346
+
+// compile-flags:-D renamed-and-removed-lints -D raw_pointer_derive
+
+// error-pattern:lint `raw_pointer_derive` has been removed
+// error-pattern:requested on the command line with `-D raw_pointer_derive`
+
+#![warn(unused)]
+
+#[deny(warnings)]
+fn main() { let unused = (); }

tests/ui/lint/lint-removed-cmdline-deny.stderr

@@ -0,0 +1,27 @@
+warning: lint `raw_pointer_derive` has been removed: using derive with raw pointers is ok
+   |
+   = note: requested on the command line with `-D raw_pointer_derive`
+
+warning: lint `raw_pointer_derive` has been removed: using derive with raw pointers is ok
+   |
+   = note: requested on the command line with `-D raw_pointer_derive`
+
+warning: lint `raw_pointer_derive` has been removed: using derive with raw pointers is ok
+   |
+   = note: requested on the command line with `-D raw_pointer_derive`
+
+error: unused variable: `unused`
+  --> $DIR/lint-removed-cmdline-deny.rs:12:17
+   |
+LL | fn main() { let unused = (); }
+   |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused`
+   |
+note: the lint level is defined here
+  --> $DIR/lint-removed-cmdline-deny.rs:11:8
+   |
+LL | #[deny(warnings)]
+   |        ^^^^^^^^
+   = note: `#[deny(unused_variables)]` implied by `#[deny(warnings)]`
+
+error: aborting due to previous error; 3 warnings emitted
+

tests/ui/lint/lint-renamed-cmdline-deny.rs

@@ -0,0 +1,8 @@
+// compile-flags:-D renamed-and-removed-lints -D bare_trait_object
+
+// error-pattern:lint `bare_trait_object` has been renamed to `bare_trait_objects`
+// error-pattern:requested on the command line with `-D bare_trait_object`
+// error-pattern:unused
+
+#[deny(unused)]
+fn main() { let unused = (); }

tests/ui/lint/lint-renamed-cmdline-deny.stderr

@@ -0,0 +1,27 @@
+warning: lint `bare_trait_object` has been renamed to `bare_trait_objects`
+   |
+   = note: requested on the command line with `-D bare_trait_object`
+
+warning: lint `bare_trait_object` has been renamed to `bare_trait_objects`
+   |
+   = note: requested on the command line with `-D bare_trait_object`
+
+warning: lint `bare_trait_object` has been renamed to `bare_trait_objects`
+   |
+   = note: requested on the command line with `-D bare_trait_object`
+
+error: unused variable: `unused`
+  --> $DIR/lint-renamed-cmdline-deny.rs:8:17
+   |
+LL | fn main() { let unused = (); }
+   |                 ^^^^^^ help: if this is intentional, prefix it with an underscore: `_unused`
+   |
+note: the lint level is defined here
+  --> $DIR/lint-renamed-cmdline-deny.rs:7:8
+   |
+LL | #[deny(unused)]
+   |        ^^^^^^
+   = note: `#[deny(unused_variables)]` implied by `#[deny(unused)]`
+
+error: aborting due to previous error; 3 warnings emitted
+

tests/ui/lint/lint-unknown-lint-cmdline-allow.rs

@@ -0,0 +1,3 @@
+// compile-flags:-A unknown-lints -D bogus -D dead_cod
+
+fn main() { }

tests/ui/lint/lint-unknown-lint-cmdline-allow.stderr

@@ -0,0 +1,21 @@
+error[E0602]: unknown lint: `bogus`
+   |
+   = note: requested on the command line with `-D bogus`
+
+error[E0602]: unknown lint: `dead_cod`
+   |
+   = help: did you mean: `dead_code`
+   = note: requested on the command line with `-D dead_cod`
+
+error[E0602]: unknown lint: `bogus`
+   |
+   = note: requested on the command line with `-D bogus`
+
+error[E0602]: unknown lint: `dead_cod`
+   |
+   = help: did you mean: `dead_code`
+   = note: requested on the command line with `-D dead_cod`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0602`.

tests/ui/lint/lint-unknown-lint-cmdline-deny.rs

@@ -0,0 +1,8 @@
+// compile-flags:-D unknown-lints -D bogus -D dead_cod
+
+// error-pattern:unknown lint: `bogus`
+// error-pattern:requested on the command line with `-D bogus`
+// error-pattern:requested on the command line with `-D dead_cod`
+// error-pattern:did you mean: `dead_code`
+
+fn main() { }

tests/ui/lint/lint-unknown-lint-cmdline-deny.stderr

@@ -0,0 +1,21 @@
+error[E0602]: unknown lint: `bogus`
+   |
+   = note: requested on the command line with `-D bogus`
+
+error[E0602]: unknown lint: `dead_cod`
+   |
+   = help: did you mean: `dead_code`
+   = note: requested on the command line with `-D dead_cod`
+
+error[E0602]: unknown lint: `bogus`
+   |
+   = note: requested on the command line with `-D bogus`
+
+error[E0602]: unknown lint: `dead_cod`
+   |
+   = help: did you mean: `dead_code`
+   = note: requested on the command line with `-D dead_cod`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0602`.