Rename isImpl to isActual in descriptors

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrBuiltinFunctionDescriptor.kt

@@ -55,7 +55,7 @@ abstract class IrBuiltinOperatorDescriptorBase(containingDeclaration: Declaratio
     override fun isSuspend(): Boolean = false
     override fun isTailrec(): Boolean = false
     override fun isExpect(): Boolean = false
-    override fun isImpl(): Boolean = false
+    override fun isActual(): Boolean = false
     override fun hasStableParameterNames(): Boolean = true
     override fun hasSynthesizedParameterNames(): Boolean = false
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrDelegateDescriptor.kt

@@ -61,7 +61,7 @@ abstract class IrDelegateDescriptorBase(
         /* lateInit = */ false,
         /* isConst = */ false,
         /* isExpect = */ false,
-        /* isImpl = */ false,
+        /* isActual = */ false,
         /* isExternal = */ false,
         /* isDelegated = */ true
 ) {