add Self from implicit type[Self] to gc too

crates/ty_python_semantic/resources/mdtest/annotations/self.md

@@ -282,8 +282,10 @@ reveal_type(C().method())  # revealed: C
 
 ## Class Methods
 
+### Explicit
+
 ```py
-from typing import Self, TypeVar
+from typing import Self
 
 class Shape:
     def foo(self: Self) -> Self:
@@ -298,6 +300,64 @@ class Circle(Shape): ...
 
 reveal_type(Shape().foo())  # revealed: Shape
 reveal_type(Shape.bar())  # revealed: Shape
+
+reveal_type(Circle().foo())  # revealed: Circle
+reveal_type(Circle.bar())  # revealed: Circle
+```
+
+### Implicit
+
+```py
+from typing import Self
+
+class Shape:
+    def foo(self) -> Self:
+        return self
+
+    @classmethod
+    def bar(cls) -> Self:
+        reveal_type(cls)  # revealed: type[Self@bar]
+        return cls()
+
+class Circle(Shape): ...
+
+reveal_type(Shape().foo())  # revealed: Shape
+reveal_type(Shape.bar())  # revealed: Shape
+
+reveal_type(Circle().foo())  # revealed: Circle
+reveal_type(Circle.bar())  # revealed: Circle
+```
+
+### Implicit in generic class
+
+```py
+from typing import Self
+
+class GenericShape[T]:
+    def foo(self) -> Self:
+        return self
+
+    @classmethod
+    def bar(cls) -> Self:
+        reveal_type(cls)  # revealed: type[Self@bar]
+        return cls()
+
+    @classmethod
+    def baz[U](cls, u: U) -> "GenericShape[U]":
+        reveal_type(cls)  # revealed: type[Self@baz]
+        return cls()
+
+class GenericCircle[T](GenericShape[T]): ...
+
+reveal_type(GenericShape().foo())  # revealed: GenericShape[Unknown]
+reveal_type(GenericShape.bar())  # revealed: GenericShape[Unknown]
+reveal_type(GenericShape[int].bar())  # revealed: GenericShape[int]
+reveal_type(GenericShape.baz(1))  # revealed: GenericShape[Literal[1]]
+
+reveal_type(GenericCircle().foo())  # revealed: GenericCircle[Unknown]
+reveal_type(GenericCircle.bar())  # revealed: GenericCircle[Unknown]
+reveal_type(GenericCircle[int].bar())  # revealed: GenericCircle[int]
+reveal_type(GenericCircle.baz(1))  # revealed: GenericShape[Literal[1]]
 ```
 
 ## Attributes

crates/ty_python_semantic/src/types/signatures.rs

@@ -732,7 +732,13 @@ impl<'db> Signature<'db> {
             // signature's generic context, too. (The generic context should include any synthetic
             // typevars created for `typing.Self`, even if the `typing.Self` annotation was added
             // implicitly.)
-            if let Type::TypeVar(self_typevar) = self_type {
+            let self_typevar = match self_type {
+                Type::TypeVar(self_typevar) => Some(self_typevar),
+                Type::SubclassOf(subclass_of) => subclass_of.into_type_var(),
+                _ => None,
+            };
+
+            if let Some(self_typevar) = self_typevar {
                 match self.generic_context.as_mut() {
                     Some(generic_context)
                         if generic_context