Auto merge of #14925 - viktorlott:inline-const-expr-as-static-str, r=HKalbasi

feat: inline const as literal

Assist: inline_const_as_literal

Evaluate and inline const variable as literal.

```rust
const STRING: &str = "Hello, World!";

fn something() -> &'static str {
    STR$0ING
}
```
->
```rust
const STRING: &str = "Hello, World!";

fn something() -> &'static str {
    "Hello, World!"
}
```

Author: bors

crates/hir/src/lib.rs

@@ -3494,6 +3494,14 @@ impl Type {
         }
     }
 
+    pub fn is_scalar(&self) -> bool {
+        matches!(self.ty.kind(Interner), TyKind::Scalar(_))
+    }
+
+    pub fn is_tuple(&self) -> bool {
+        matches!(self.ty.kind(Interner), TyKind::Tuple(..))
+    }
+
     pub fn remove_ref(&self) -> Option<Type> {
         match &self.ty.kind(Interner) {
             TyKind::Ref(.., ty) => Some(self.derived(ty.clone())),