Add changelog for 2.1.21-RC

Author: woainikk

ChangeLog.md

@@ -1,3 +1,90 @@
+## 2.1.21-RC
+
+### Backend. Native. Debug
+
+- [`KT-75991`](https://youtrack.jetbrains.com/issue/KT-75991) Xcode 16.3: Fix lldb stepping test over an inline function
+
+### Compiler
+
+- [`KT-75992`](https://youtrack.jetbrains.com/issue/KT-75992) Xcode 16.3: stacktraces on simulators are not symbolicated
+- [`KT-76663`](https://youtrack.jetbrains.com/issue/KT-76663) KJS: KotlinNothingValueException caused by expression return since 2.1.20
+- [`KT-75756`](https://youtrack.jetbrains.com/issue/KT-75756) Backend Internal error: Exception during IR lowering when trying to access variable from providedProperties in class within kotlin custom script
+- [`KT-76209`](https://youtrack.jetbrains.com/issue/KT-76209) CONFLICTING_UPPER_BOUNDS on `Nothing` bound
+- [`KT-70352`](https://youtrack.jetbrains.com/issue/KT-70352) K2: False-negative CONFLICTING_UPPER_BOUNDS on `Nothing` bound
+- [`KT-74739`](https://youtrack.jetbrains.com/issue/KT-74739) Native: "IllegalArgumentException: All constructors should've been lowered: FUNCTION_REFERENCE"
+- [`KT-75483`](https://youtrack.jetbrains.com/issue/KT-75483) Native: redundant unboxing generated with smart cast
+- [`KT-71425`](https://youtrack.jetbrains.com/issue/KT-71425) IR Inliner: investigate return type of an inlined block
+
+### Compose compiler
+- [`b/408013789`](https://issuetracker.google.com/issues/408013789) Add missing return for the default function wrappers
+- [`b/405541364`](https://issuetracker.google.com/issues/405541364) Realize coalescable children in the body of `key` call
+- [`b/401484249`](https://issuetracker.google.com/issues/401484249) Generate a group around `Array` constructor call
+- [`b/400380396`](https://issuetracker.google.com/issues/400380396) Fix missing `endMovableGroup` call with early return in `key` function
+
+### Native
+
+- [`KT-76252`](https://youtrack.jetbrains.com/issue/KT-76252) Native: executable crash with generic value classes with 2.1.20
+
+### Native. C and ObjC Import
+
+- [`KT-75781`](https://youtrack.jetbrains.com/issue/KT-75781) Xcode 16.3: Fix cinterop tests failing with fatal error: could not build module '_stdint'
+
+### Native. Runtime. Memory
+
+- [`KT-74280`](https://youtrack.jetbrains.com/issue/KT-74280) Native: GC.collect crashes with -Xallocator=std
+
+### Tools. CLI
+
+- [`KT-74663`](https://youtrack.jetbrains.com/issue/KT-74663) kotlinc-js CLI: not providing -ir-output-dir results in NullPointerException
+
+### Tools. Compiler Plugins
+
+- [`KT-76162`](https://youtrack.jetbrains.com/issue/KT-76162) "IllegalStateException: No mapping for symbol: VALUE_PARAMETER INSTANCE_RECEIVER" after updating to 2.1.20
+
+### Tools. Gradle
+
+- [`KT-73142`](https://youtrack.jetbrains.com/issue/KT-73142) Kotlin Gradle plugin: Remove usage of Gradle's internal ExecHandleBuilder
+- [`KT-73684`](https://youtrack.jetbrains.com/issue/KT-73684) Run integration tests against Gradle 8.12
+- [`KT-74889`](https://youtrack.jetbrains.com/issue/KT-74889) Compile against Gradle 8.13 API
+- [`KT-74887`](https://youtrack.jetbrains.com/issue/KT-74887) Compatibility with Gradle 8.13 release
+- [`KT-36004`](https://youtrack.jetbrains.com/issue/KT-36004) Update 'org.gradle.usage' attribute rules to support the 'JAVA_API' and 'JAVA_RUNTIME' value
+- [`KT-72694`](https://youtrack.jetbrains.com/issue/KT-72694) Accessing Task.project during execution is being deprecated in Gradle 8.12
+- [`KT-74890`](https://youtrack.jetbrains.com/issue/KT-74890) Run Gradle integrations test against Gradle 8.13 release
+- [`KT-73682`](https://youtrack.jetbrains.com/issue/KT-73682) Compatibility with Gradle 8.12 release
+- [`KT-73968`](https://youtrack.jetbrains.com/issue/KT-73968) KotlinDependencyManagement tries to mutate configuration after it was resolved
+- [`KT-73683`](https://youtrack.jetbrains.com/issue/KT-73683) Compile against Gradle API 8.12
+
+### Tools. Gradle. JS
+
+- [`KT-74735`](https://youtrack.jetbrains.com/issue/KT-74735) KGP uses Gradle internal `CompositeProjectComponentArtifactMetadata`
+- [`KT-71879`](https://youtrack.jetbrains.com/issue/KT-71879) Notice of upcoming deprecation for Boolean 'is-' properties in Gradle Groovy scripts
+
+### Tools. Gradle. Multiplatform
+
+- [`KT-75808`](https://youtrack.jetbrains.com/issue/KT-75808) KGP: MPP with jvm target and Gradle java-test-fixtures is broken
+- [`KT-75605`](https://youtrack.jetbrains.com/issue/KT-75605) Dependency resolution fails in commonTest/nativeTest source sets for KMP module when depending on another project due to missing PSM
+- [`KT-75512`](https://youtrack.jetbrains.com/issue/KT-75512) Maven-publish: ArtifactId is not correct  in`pom` file with customized `withXml`
+
+### Tools. Incremental Compile
+
+- [`KT-62555`](https://youtrack.jetbrains.com/issue/KT-62555) Wrong ABI fingerprint for inline function containing a lambda
+
+### Tools. Kapt
+
+- [`KT-75936`](https://youtrack.jetbrains.com/issue/KT-75936) K2 KAPT: unsupported FIR element kinds in constant evaluation
+- [`KT-75942`](https://youtrack.jetbrains.com/issue/KT-75942) K2 KAPT: underscore not allowed here
+
+### Tools. Scripts
+
+- [`KT-76424`](https://youtrack.jetbrains.com/issue/KT-76424) Dependencies in main.kts not working with 2.1.20
+- [`KT-76296`](https://youtrack.jetbrains.com/issue/KT-76296) Kotlin script compiler crashes when secondary constructor calls a function
+- [`KT-75589`](https://youtrack.jetbrains.com/issue/KT-75589) Scripts: "IndexOutOfBoundsException in jdk.internal.util.Preconditions.outOfBounds" when trying to extend a class which uses global variable
+
+### Tools. Wasm
+
+- [`KT-76161`](https://youtrack.jetbrains.com/issue/KT-76161) Wasm: "export startUnitTests was not found" after updating to Kotlin 2.1.20
+
+
 ## 2.1.20-RC3
 
 ### Compiler