K2 plugins: set proper 'expect' flag for all member declarations

Related to KT-59299

compiler/fir/plugin-utils/src/org/jetbrains/kotlin/fir/plugin/ClassBuildingContext.kt

@@ -136,7 +136,11 @@ public fun FirExtension.createNestedClass(
     classKind: ClassKind = ClassKind.CLASS,
     config: ClassBuildingContext.() -> Unit = {}
 ): FirRegularClass {
-    return ClassBuildingContext(session, key, owner, owner.classId.createNestedClassId(name), classKind).apply(config).build()
+    return ClassBuildingContext(session, key, owner, owner.classId.createNestedClassId(name), classKind).apply(config).apply {
+        status {
+            isExpect = owner.isExpect
+        }
+    }.build()
 }
 
 /**

compiler/fir/plugin-utils/src/org/jetbrains/kotlin/fir/plugin/ConstructorBuildingContext.kt

@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
 import org.jetbrains.kotlin.fir.declarations.FirTypeParameterRef
 import org.jetbrains.kotlin.fir.declarations.builder.*
 import org.jetbrains.kotlin.fir.declarations.origin
+import org.jetbrains.kotlin.fir.declarations.utils.isExpect
 import org.jetbrains.kotlin.fir.declarations.utils.isInner
 import org.jetbrains.kotlin.fir.expressions.buildResolvedArgumentList
 import org.jetbrains.kotlin.fir.expressions.builder.buildDelegatedConstructorCall
@@ -122,7 +123,11 @@ public fun FirExtension.createConstructor(
     generateDelegatedNoArgConstructorCall: Boolean = false,
     config: ConstructorBuildingContext.() -> Unit = {}
 ): FirConstructor {
-    return ConstructorBuildingContext(session, key, owner, isPrimary).apply(config).build().also {
+    return ConstructorBuildingContext(session, key, owner, isPrimary).apply(config).apply {
+        status {
+            isExpect = owner.isExpect
+        }
+    }.build().also {
         if (generateDelegatedNoArgConstructorCall) {
             it.generateNoArgDelegatingConstructorCall()
         }

compiler/fir/plugin-utils/src/org/jetbrains/kotlin/fir/plugin/PropertyBuildingContext.kt

@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.fir.declarations.builder.buildReceiverParameter
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyBackingField
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyGetter
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertySetter
+import org.jetbrains.kotlin.fir.declarations.utils.isExpect
 import org.jetbrains.kotlin.fir.extensions.FirExtension
 import org.jetbrains.kotlin.fir.moduleData
 import org.jetbrains.kotlin.fir.resolve.defaultType
@@ -156,7 +157,11 @@ public fun FirExtension.createMemberProperty(
     config: PropertyBuildingContext.() -> Unit = {}
 ): FirProperty {
     val callableId = CallableId(owner.classId, name)
-    return PropertyBuildingContext(session, key, owner, callableId, returnTypeProvider, isVal, hasBackingField).apply(config).build()
+    return PropertyBuildingContext(session, key, owner, callableId, returnTypeProvider, isVal, hasBackingField).apply(config).apply {
+        status {
+            isExpect = owner.isExpect
+        }
+    }.build()
 }
 
 /**

compiler/fir/plugin-utils/src/org/jetbrains/kotlin/fir/plugin/SimpleFunctionBuildingContext.kt

@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.fir.declarations.FirTypeParameter
 import org.jetbrains.kotlin.fir.declarations.builder.buildReceiverParameter
 import org.jetbrains.kotlin.fir.declarations.builder.buildSimpleFunction
 import org.jetbrains.kotlin.fir.declarations.origin
+import org.jetbrains.kotlin.fir.declarations.utils.isExpect
 import org.jetbrains.kotlin.fir.extensions.FirExtension
 import org.jetbrains.kotlin.fir.moduleData
 import org.jetbrains.kotlin.fir.resolve.defaultType
@@ -113,7 +114,11 @@ public fun FirExtension.createMemberFunction(
     config: SimpleFunctionBuildingContext.() -> Unit = {}
 ): FirSimpleFunction {
     val callableId = CallableId(owner.classId, name)
-    return SimpleFunctionBuildingContext(session, key, owner, callableId, returnTypeProvider).apply(config).build()
+    return SimpleFunctionBuildingContext(session, key, owner, callableId, returnTypeProvider).apply(config).apply {
+        status {
+            isExpect = owner.isExpect
+        }
+    }.build()
 }
 
 /**