IR Scripting: allow to specify nullable types for provided props...

but only explicitly. This does not fix a breaking change described in
#KT-52120, because it seems the correct behavior, but it allows
to "workaround" the problem by specifying nullability explicitly.
Also improve handling of nullable bindings in JSR-223.
#KT-49173 fixed
#KT-51213 fixed

plugins/scripting/scripting-compiler-impl/src/org/jetbrains/kotlin/scripting/definitions/KotlinScriptDefinitionAdapterFromNewAPI.kt

@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.psi.KtScript
 import kotlin.reflect.KClass
 import kotlin.reflect.KType
 import kotlin.reflect.full.starProjectedType
+import kotlin.reflect.full.withNullability
 import kotlin.script.experimental.api.*
 import kotlin.script.experimental.dependencies.DependenciesResolver
 import kotlin.script.experimental.host.ScriptingHostConfiguration
@@ -68,12 +69,12 @@ abstract class KotlinScriptDefinitionAdapterFromNewAPIBase : KotlinScriptDefinit
     override val implicitReceivers: List<KType> by lazy(LazyThreadSafetyMode.PUBLICATION) {
         scriptCompilationConfiguration[ScriptCompilationConfiguration.implicitReceivers]
             .orEmpty()
-            .map { getScriptingClass(it).starProjectedType }
+            .map { getScriptingClass(it).starProjectedType.withNullability(it.isNullable) }
     }
 
     override val providedProperties: List<Pair<String, KType>> by lazy(LazyThreadSafetyMode.PUBLICATION) {
         scriptCompilationConfiguration[ScriptCompilationConfiguration.providedProperties]
-            ?.map { (k, v) -> k to getScriptingClass(v).starProjectedType }.orEmpty()
+            ?.map { (k, v) -> k to getScriptingClass(v).starProjectedType.withNullability(v.isNullable) }.orEmpty()
     }
 
     @Deprecated("temporary workaround for missing functionality, will be replaced by the new API soon")

plugins/scripting/scripting-compiler-impl/src/org/jetbrains/kotlin/scripting/resolve/LazyScriptDescriptor.kt

@@ -274,7 +274,7 @@ class LazyScriptDescriptor(
         scriptCompilationConfiguration()[ScriptCompilationConfiguration.providedProperties].orEmpty()
             .mapNotNull { (name, type) ->
                 findTypeDescriptor(getScriptingClass(type), Errors.MISSING_SCRIPT_PROVIDED_PROPERTY_CLASS)
-                    ?.let { name.toValidJvmIdentifier() to it }
+                    ?.let { name.toValidJvmIdentifier() to it.defaultType.makeNullableAsSpecified(type.isNullable) }
             }.map { (name, classDescriptor) ->
                 ScriptProvidedPropertyDescriptor(
                     Name.identifier(name),

plugins/scripting/scripting-compiler-impl/src/org/jetbrains/kotlin/scripting/resolve/ScriptProvidedPropertyDescriptor.kt

@@ -9,10 +9,11 @@ import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.descriptors.impl.PropertyDescriptorImpl
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.types.KotlinType
 
 class ScriptProvidedPropertyDescriptor(
     name: Name,
-    typeDescriptor: ClassDescriptor,
+    type: KotlinType,
     receiver: ReceiverParameterDescriptor?,
     isVar: Boolean,
     script: ScriptDescriptor
@@ -30,7 +31,7 @@ class ScriptProvidedPropertyDescriptor(
     /* isDelegated = */ false
 ) {
     init {
-        setType(typeDescriptor.defaultType, emptyList(), receiver, null, emptyList())
+        setType(type, emptyList(), receiver, null, emptyList())
         // TODO: consider delegation instead
         initialize(null, null, null, null)
     }