KT-43217 Encode @EnhancedNullability types in IdSignature

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/MangleConstant.kt

@@ -16,6 +16,7 @@ enum class MangleConstant(val prefix: Char, val separator: Char, val suffix: Cha
         const val VAR_ARG_MARK = "..."
         const val STAR_MARK = '*'
         const val Q_MARK = '?'
+        const val ENHANCED_NULLABILITY_MARK = "{EnhancedNullability}"
         const val EXPECT_MARK = "#expect"
         const val UNKNOWN_MARK = "<unknown>"
         const val DYNAMIC_MARK = "<dynamic>"

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/descriptor/DescriptorMangleComputer.kt

@@ -10,7 +10,9 @@ import org.jetbrains.kotlin.backend.common.serialization.mangle.MangleConstant
 import org.jetbrains.kotlin.backend.common.serialization.mangle.MangleMode
 import org.jetbrains.kotlin.backend.common.serialization.mangle.collectForMangler
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.load.java.typeEnhancement.hasEnhancedNullability
 import org.jetbrains.kotlin.types.*
+import org.jetbrains.kotlin.types.checker.SimpleClassicTypeSystemContext
 import org.jetbrains.kotlin.types.typeUtil.isUnit
 import org.jetbrains.kotlin.utils.addToStdlib.ifNotEmpty
 
@@ -188,6 +190,11 @@ abstract class DescriptorMangleComputer(protected val builder: StringBuilder, pr
                 }
 
                 if (type.isMarkedNullable) tBuilder.appendSignature(MangleConstant.Q_MARK)
+
+                // Disambiguate between 'double' and '@NotNull java.lang.Double' types in mixed Java/Kotlin class hierarchies
+                if (SimpleClassicTypeSystemContext.hasEnhancedNullability(type)) {
+                    tBuilder.appendSignature(MangleConstant.ENHANCED_NULLABILITY_MARK)
+                }
             }
             is DynamicType -> tBuilder.appendSignature(MangleConstant.DYNAMIC_MARK)
             is FlexibleType -> {

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/ir/IrMangleComputer.kt

@@ -12,9 +12,11 @@ import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrTypeParameterSymbol
 import org.jetbrains.kotlin.ir.types.*
+import org.jetbrains.kotlin.ir.util.hasAnnotation
 import org.jetbrains.kotlin.ir.util.isVararg
 import org.jetbrains.kotlin.ir.util.render
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
+import org.jetbrains.kotlin.load.java.JvmAnnotationNames
 import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.utils.addToStdlib.ifNotEmpty
 
@@ -178,6 +180,10 @@ abstract class IrMangleComputer(protected val builder: StringBuilder, private va
                 }
 
                 if (type.hasQuestionMark) tBuilder.appendSignature(MangleConstant.Q_MARK)
+
+                if (type.hasAnnotation(JvmAnnotationNames.ENHANCED_NULLABILITY_ANNOTATION)) {
+                    tBuilder.append(MangleConstant.ENHANCED_NULLABILITY_MARK)
+                }
             }
             is IrDynamicType -> tBuilder.appendSignature(MangleConstant.DYNAMIC_MARK)
             is IrErrorType -> tBuilder.appendSignature(MangleConstant.ERROR_MARK)

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/signature/IdSignatureDescriptor.kt

@@ -6,7 +6,6 @@
 package org.jetbrains.kotlin.backend.common.serialization.signature
 
 import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.descriptors.WrappedDeclarationDescriptor
 import org.jetbrains.kotlin.ir.util.IdSignature
 import org.jetbrains.kotlin.ir.util.IdSignatureComposer