[FIR] Add FirCodeFragment

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/DeclarationUtils.kt

@@ -87,3 +87,7 @@ var FirConstructor.originalConstructorIfTypeAlias: FirConstructor? by FirDeclara
 
 val FirConstructorSymbol.isTypeAliasedConstructor: Boolean
     get() = fir.originalConstructorIfTypeAlias != null
+
+private object CodeFragmentTowerDataContext : FirDeclarationDataKey()
+
+var FirCodeFragment.towerDataContext: FirTowerDataContext? by FirDeclarationDataRegistry.data(CodeFragmentTowerDataContext)

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/dfa/cfg/CFGNode.kt

@@ -300,6 +300,19 @@ class ScriptExitNode(owner: ControlFlowGraph, override val fir: FirScript, level
     }
 }
 
+// ----------------------------------- Code Fragments ------------------------------------------
+
+class CodeFragmentEnterNode(owner: ControlFlowGraph, override val fir: FirCodeFragment, level: Int) : CFGNode<FirCodeFragment>(owner, level), GraphEnterNodeMarker {
+    override fun <R, D> accept(visitor: ControlFlowGraphVisitor<R, D>, data: D): R {
+        return visitor.visitCodeFragmentEnterNode(this, data)
+    }
+}
+
+class CodeFragmentExitNode(owner: ControlFlowGraph, override val fir: FirCodeFragment, level: Int) : CFGNode<FirCodeFragment>(owner, level), GraphExitNodeMarker {
+    override fun <R, D> accept(visitor: ControlFlowGraphVisitor<R, D>, data: D): R {
+        return visitor.visitCodeFragmentExitNode(this, data)
+    }
+}
 // ----------------------------------- Property -----------------------------------
 
 class PropertyInitializerEnterNode(owner: ControlFlowGraph, override val fir: FirProperty, level: Int) : CFGNode<FirProperty>(owner, level),

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/dfa/cfg/CFGNodeRenderer.kt

@@ -106,6 +106,9 @@ fun CFGNode<*>.render(): String =
                 is ScriptEnterNode -> "Enter class ${fir.name}"
                 is ScriptExitNode -> "Exit class ${fir.name}"
 
+                is CodeFragmentEnterNode -> "Enter code fragment"
+                is CodeFragmentExitNode -> "Exit code fragment"
+
                 is FakeExpressionEnterNode -> "Enter fake expression"
 
                 is EnterValueParameterNode -> "Enter default value of ${fir.name}"

compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/dfa/cfg/ControlFlowGraphVisitor.kt

@@ -90,6 +90,16 @@ abstract class ControlFlowGraphVisitor<out R, in D> {
         return visitNode(node, data)
     }
 
+    // ----------------------------------- Code Fragments ------------------------------------------
+
+    open fun visitCodeFragmentEnterNode(node: CodeFragmentEnterNode, data: D): R {
+        return visitNode(node, data)
+    }
+
+    open fun visitCodeFragmentExitNode(node: CodeFragmentExitNode, data: D): R {
+        return visitNode(node, data)
+    }
+
     // ----------------------------------- Property -----------------------------------
 
     open fun visitPropertyInitializerEnterNode(node: PropertyInitializerEnterNode, data: D): R {