KT-52743 IR: Fix null checks in Elvis operators

compiler/ir/backend.jvm/lower/src/org/jetbrains/kotlin/backend/jvm/lower/JvmSafeCallChainFoldingLowering.kt

@@ -17,7 +17,7 @@ import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.dump
 import org.jetbrains.kotlin.ir.util.hasAnnotation
-import org.jetbrains.kotlin.ir.util.isTrivial
+import org.jetbrains.kotlin.ir.util.isConstantLike
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames
@@ -121,7 +121,7 @@ class JvmSafeCallChainFoldingLowering(val context: JvmBackendContext) : FileLowe
         IrConstImpl.boolean(startOffset, endOffset, context.irBuiltIns.booleanType, false)
 
     private fun irValNotNull(startOffset: Int, endOffset: Int, irVariable: IrVariable): IrExpression =
-        if (irVariable.type.isJvmNullable() || irVariable.initializer?.isTrivial() != true)
+        if (irVariable.type.isJvmNullable() || irVariable.initializer?.isConstantLike != true)
             IrGetValueImpl(startOffset, endOffset, irVariable.symbol).irEqEqNull().irNot()
         else
             irTrue(startOffset, endOffset)

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -596,6 +596,10 @@ fun IrExpression.isTrivial() =
             this is IrGetObjectValue ||
             this is IrErrorExpressionImpl
 
+val IrExpression.isConstantLike: Boolean
+    get() = this is IrConst<*> || this is IrGetSingletonValue
+            || this is IrGetValue && this.symbol.owner.origin == IrDeclarationOrigin.INSTANCE_RECEIVER
+
 fun IrExpression.shallowCopy(): IrExpression =
     shallowCopyOrNull()
         ?: error("Not a copyable expression: ${render()}")