Do not write version requirements for InlineClasses

Language feature InlineClasses is enabled since 1.3. The current lowest
supported language version is 1.4, so any compiler that can read
binaries produced by the current compiler also supports inline classes,
which means that the version requirement is not needed anymore.

No issue reported because it's mostly not a user-visible change. The
main effect is that it reduces differences in metadata between K1 and
K2, because K2 never supported writing this version requirement properly
due to the TODO in `hasInlineClassTypesInSignature`.

compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.kt

@@ -25,8 +25,10 @@ import org.jetbrains.kotlin.metadata.serialization.MutableTypeTable
 import org.jetbrains.kotlin.metadata.serialization.MutableVersionRequirementTable
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.resolve.*
+import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.DescriptorUtils.isEnumEntry
+import org.jetbrains.kotlin.resolve.MemberComparator
+import org.jetbrains.kotlin.resolve.RequireKotlinConstants
 import org.jetbrains.kotlin.resolve.calls.components.isActualParameterWithAnyExpectedDefault
 import org.jetbrains.kotlin.resolve.constants.EnumValue
 import org.jetbrains.kotlin.resolve.constants.IntValue
@@ -35,13 +37,13 @@ import org.jetbrains.kotlin.resolve.constants.StringValue
 import org.jetbrains.kotlin.resolve.descriptorUtil.inlineClassRepresentation
 import org.jetbrains.kotlin.resolve.descriptorUtil.multiFieldValueClassRepresentation
 import org.jetbrains.kotlin.resolve.descriptorUtil.nonSourceAnnotations
+import org.jetbrains.kotlin.resolve.isValueClass
 import org.jetbrains.kotlin.serialization.deserialization.ProtoEnumFlags
 import org.jetbrains.kotlin.serialization.deserialization.descriptorVisibility
 import org.jetbrains.kotlin.serialization.deserialization.memberKind
 import org.jetbrains.kotlin.types.*
 import org.jetbrains.kotlin.types.extensions.TypeAttributeTranslators
 import org.jetbrains.kotlin.types.typeUtil.contains
-import org.jetbrains.kotlin.types.typeUtil.immediateSupertypes
 import org.jetbrains.kotlin.types.typeUtil.replaceAnnotations
 import java.util.*
 
@@ -193,8 +195,6 @@ class DescriptorSerializer private constructor(
 
         plugins.forEach { it.afterClass(classDescriptor, builder, versionRequirementTable, this, extension) }
 
-        writeVersionRequirementForInlineClasses(classDescriptor, builder, versionRequirementTable)
-
         if (metDefinitelyNotNullType) {
             builder.addVersionRequirement(
                 writeLanguageVersionRequirement(LanguageFeature.DefinitelyNonNullableTypes, versionRequirementTable)
@@ -207,28 +207,6 @@ class DescriptorSerializer private constructor(
         return builder
     }
 
-    private fun writeVersionRequirementForInlineClasses(
-        classDescriptor: ClassDescriptor,
-        builder: ProtoBuf.Class.Builder,
-        versionRequirementTable: MutableVersionRequirementTable
-    ) {
-        if (!classDescriptor.isInlineClass() && !classDescriptor.hasInlineClassTypesInSignature()) return
-
-        builder.addVersionRequirement(
-            writeLanguageVersionRequirement(LanguageFeature.InlineClasses, versionRequirementTable)
-        )
-    }
-
-    private fun ClassDescriptor.hasInlineClassTypesInSignature(): Boolean {
-        for (typeParameter in declaredTypeParameters) {
-            if (typeParameter.upperBounds.any { it.contains(UnwrappedType::isInlineClassType) }) return true
-        }
-
-        if (defaultType.immediateSupertypes().any { supertype -> supertype.contains(UnwrappedType::isInlineClassType) }) return true
-
-        return false
-    }
-
     fun propertyProto(descriptor: PropertyDescriptor): ProtoBuf.Property.Builder? {
         val builder = ProtoBuf.Property.newBuilder()
 
@@ -322,10 +300,6 @@ class DescriptorSerializer private constructor(
                 builder.addVersionRequirement(writeVersionRequirementDependingOnCoroutinesVersion())
             }
 
-            if (descriptor.hasInlineClassTypesInSignature()) {
-                builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.InlineClasses))
-            }
-
             if (local.metDefinitelyNotNullType) {
                 builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.DefinitelyNonNullableTypes))
             }
@@ -419,10 +393,6 @@ class DescriptorSerializer private constructor(
                 builder.addVersionRequirement(writeVersionRequirementDependingOnCoroutinesVersion())
             }
 
-            if (descriptor.hasInlineClassTypesInSignature()) {
-                builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.InlineClasses))
-            }
-
             if (local.metDefinitelyNotNullType) {
                 builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.DefinitelyNonNullableTypes))
             }
@@ -455,10 +425,6 @@ class DescriptorSerializer private constructor(
                 builder.addVersionRequirement(writeVersionRequirementDependingOnCoroutinesVersion())
             }
 
-            if (descriptor.hasInlineClassTypesInSignature()) {
-                builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.InlineClasses))
-            }
-
             if (local.metDefinitelyNotNullType) {
                 builder.addVersionRequirement(writeVersionRequirement(LanguageFeature.DefinitelyNonNullableTypes))
             }
@@ -480,10 +446,6 @@ class DescriptorSerializer private constructor(
         return allTypesFromSignature().any { type -> type.contains(UnwrappedType::isSuspendFunctionTypeOrSubtype) }
     }
 
-    private fun CallableMemberDescriptor.hasInlineClassTypesInSignature(): Boolean {
-        return allTypesFromSignature().any { type -> type.contains(UnwrappedType::isInlineClassType) }
-    }
-
     private fun CallableMemberDescriptor.allTypesFromSignature(): List<KotlinType> {
         return listOfNotNull(
             extensionReceiverParameter?.type,
@@ -760,9 +722,6 @@ class DescriptorSerializer private constructor(
         return writeLanguageVersionRequirement(languageFeature, this)
     }
 
-    private fun MutableVersionRequirementTable.writeCompilerVersionRequirement(major: Int, minor: Int, patch: Int): Int =
-        writeCompilerVersionRequirement(major, minor, patch, this)
-
     // Returns a list of indices into versionRequirementTable, or empty list if there's no @RequireKotlin on the descriptor
     private fun MutableVersionRequirementTable.serializeVersionRequirements(descriptor: DeclarationDescriptor): List<Int> =
         descriptor.annotations
@@ -925,17 +884,6 @@ class DescriptorSerializer private constructor(
             )
         }
 
-        fun writeCompilerVersionRequirement(
-            major: Int,
-            minor: Int,
-            patch: Int,
-            versionRequirementTable: MutableVersionRequirementTable
-        ): Int = writeVersionRequirement(
-            major, minor, patch,
-            ProtoBuf.VersionRequirement.VersionKind.COMPILER_VERSION,
-            versionRequirementTable
-        )
-
         fun writeVersionRequirement(
             major: Int,
             minor: Int,