Implement the #[sanitize(..)] attribute

This change implements the #[sanitize(..)] attribute, which opts to
replace the currently unstable #[no_sanitize]. Essentially the new
attribute works similar as #[no_sanitize], just with more flexible
options regarding where it is applied. E.g. it is possible to turn
a certain sanitizer either on or off:
`#[sanitize(address = "on|off")]`

This attribute now also applies to more places, e.g. it is possible
to turn off a sanitizer for an entire module or impl block:
```rust
\#[sanitize(address = "off")]
mod foo {
    fn unsanitized(..) {}

    #[sanitize(address = "on")]
    fn sanitized(..) {}
}

\#[sanitize(thread = "off")]
impl MyTrait for () {
    ...
}
```

This attribute is enabled behind the unstable `sanitize` feature.

1 files changed, 8 insertions, 0 deletions

diff --git a/compiler/rustc_codegen_ssa/src/errors.rs b/compiler/rustc_codegen_ssa/src/errors.rs
index 7ac830bcda9..913e0025f2e 100644
--- a/compiler/rustc_codegen_ssa/src/errors.rs
+++ b/compiler/rustc_codegen_ssa/src/errors.rs
@@ -1129,6 +1129,14 @@ pub(crate) struct InvalidNoSanitize {
 }
 
 #[derive(Diagnostic)]
+#[diag(codegen_ssa_invalid_sanitize)]
+#[note]
+pub(crate) struct InvalidSanitize {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
 #[diag(codegen_ssa_target_feature_safe_trait)]
 pub(crate) struct TargetFeatureSafeTrait {
     #[primary_span]