[NI] There is no need in copying constraint storage as it read-only

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/PostponedArgumentsAnalyzer.kt

@@ -102,7 +102,7 @@ class PostponedArgumentsAnalyzer(
         }
 
         if (inferenceSession != null) {
-            val storageSnapshot = c.getBuilder().copyCurrentStorage()
+            val storageSnapshot = c.getBuilder().currentStorage()
 
             val postponedVariables = inferenceSession.inferPostponedVariables(storageSnapshot)
 

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/ConstraintSystemBuilder.kt

@@ -49,7 +49,7 @@ interface ConstraintSystemBuilder : ConstraintSystemOperation {
 
     fun buildCurrentSubstitutor(): NewTypeSubstitutor
 
-    fun copyCurrentStorage(): ConstraintStorage
+    fun currentStorage(): ConstraintStorage
 }
 
 fun ConstraintSystemBuilder.addSubtypeConstraintIfCompatible(

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/MutableConstraintStorage.kt

@@ -97,32 +97,4 @@ internal class MutableConstraintStorage : ConstraintStorage {
     override val hasContradiction: Boolean get() = errors.any { !it.candidateApplicability.isSuccess }
     override val fixedTypeVariables: MutableMap<TypeConstructor, UnwrappedType> = LinkedHashMap()
     override val postponedTypeVariables: ArrayList<NewTypeVariable> = ArrayList()
-
-    fun copy(): ConstraintStorage {
-        return object : ConstraintStorage {
-            override val allTypeVariables: Map<TypeConstructor, NewTypeVariable> =
-                this@MutableConstraintStorage.allTypeVariables.toMap()
-
-            override val notFixedTypeVariables: Map<TypeConstructor, VariableWithConstraints> =
-                this@MutableConstraintStorage.notFixedTypeVariables.toMap()
-
-            override val initialConstraints: List<InitialConstraint> =
-                this@MutableConstraintStorage.initialConstraints.toList()
-
-            override val maxTypeDepthFromInitialConstraints: Int =
-                this@MutableConstraintStorage.maxTypeDepthFromInitialConstraints
-
-            override val errors: List<KotlinCallDiagnostic> =
-                this@MutableConstraintStorage.errors.toList()
-
-            override val hasContradiction: Boolean =
-                this@MutableConstraintStorage.hasContradiction
-
-            override val fixedTypeVariables: Map<TypeConstructor, UnwrappedType> =
-                this@MutableConstraintStorage.fixedTypeVariables.toMap()
-
-            override val postponedTypeVariables: List<NewTypeVariable> =
-                this@MutableConstraintStorage.postponedTypeVariables.toList()
-        }
-    }
 }

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/NewConstraintSystemImpl.kt

@@ -278,9 +278,9 @@ class NewConstraintSystemImpl(
         return storage.postponedTypeVariables.associate { it to NonFixedType(it.freshTypeConstructor, it.defaultType.isMarkedNullable) }
     }
 
-    override fun copyCurrentStorage(): ConstraintStorage {
+    override fun currentStorage(): ConstraintStorage {
         checkState(State.BUILDING, State.COMPLETION)
-        return storage.copy()
+        return storage
     }
 
     // PostponedArgumentsAnalyzer.Context