Build: fix "unknown enum constant" warning on Nls.Capitalization

#KTI-88 Fixed

core/util.runtime/src/org/jetbrains/annotations/Nls.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.annotations;
+
+import java.lang.annotation.*;
+
+/**
+ * This is a copy of `org.jetbrains.annotations.Nls` from IntelliJ. It's need in the build because Kotlin depends on annotations-13.0,
+ * an older version where Nls doesn't have `capitalization`, whereas new versions of the IntelliJ platform reference it in the bytecode.
+ * Since we intentionally remove the newer annotations artifact from the intellij-core dependency and use version 13.0 in the build,
+ * javac wouldn't find the class file Nls$Capitalization referenced in the bytecode, and would report a non-suppressible warning
+ * for each usage site of it in IntelliJ binaries.
+ */
+@Documented
+@Retention(RetentionPolicy.CLASS)
+@Target({ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER, ElementType.LOCAL_VARIABLE, ElementType.TYPE, ElementType.PACKAGE})
+public @interface Nls {
+    Capitalization capitalization() default Capitalization.NotSpecified;
+
+    enum Capitalization { NotSpecified, Title, Sentence }
+}

libraries/reflect/build.gradle.kts

@@ -109,6 +109,7 @@ val reflectShadowJar by task<ShadowJar> {
     configurations = listOf(embedded)
 
     exclude("**/*.proto")
+    exclude("org/jetbrains/annotations/Nls*.class")
 
     if (kotlinBuildProperties.relocation) {
         mergeServiceFiles()