Refactoring: move getRepresentativeUpperBound method to core

Plus prettify it a bit

compiler/backend/src/org/jetbrains/kotlin/codegen/state/inlineClassManglingUtils.kt

@@ -6,11 +6,11 @@
 package org.jetbrains.kotlin.codegen.state
 
 import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.load.kotlin.getRepresentativeUpperBound
 import org.jetbrains.kotlin.resolve.InlineClassDescriptorResolver
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameUnsafe
 import org.jetbrains.kotlin.resolve.jvm.*
 import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.typeUtil.representativeUpperBound
 import java.security.MessageDigest
 import java.util.*
 
@@ -44,7 +44,7 @@ private fun getSignatureElementForMangling(type: KotlinType): String = buildStri
         }
 
         is TypeParameterDescriptor -> {
-            append(getSignatureElementForMangling(getRepresentativeUpperBound(descriptor)))
+            append(getSignatureElementForMangling(descriptor.representativeUpperBound))
         }
     }
 }