Don't remove nullability assertions of anonymous object transformation

#KT-19910 Fixed

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/MethodInliner.kt

@@ -82,8 +82,12 @@ class MethodInliner(
 
         //substitute returns with "goto end" instruction to keep non local returns in lambdas
         val end = Label()
+        val isTransformingAnonymousObject = nodeRemapper is RegeneratedLambdaFieldRemapper
         transformedNode = doInline(transformedNode)
-        removeClosureAssertions(transformedNode)
+        if (!isTransformingAnonymousObject) {
+            //don't remove assertion in transformed anonymous object
+            removeClosureAssertions(transformedNode)
+        }
         transformedNode.instructions.resetLabels()
 
         val resultNode = MethodNode(
@@ -93,7 +97,7 @@ class MethodInliner(
         val visitor = RemapVisitor(
                 resultNode, remapper, nodeRemapper,
                 /*copy annotation and attributes*/
-                nodeRemapper is RegeneratedLambdaFieldRemapper
+                isTransformingAnonymousObject
         )
         try {
             transformedNode.accept(visitor)

compiler/testData/codegen/boxAgainstJava/inline/kt19910.kt

@@ -0,0 +1,39 @@
+// FILE: J.java
+// FULL_JDK
+// WITH_RUNTIME
+// TARGET_BACKEND: JVM
+public class J {
+    public interface Consumer {
+        void accept(String p);
+    }
+
+    public static void invokeWithNull(Consumer x) {
+        x.accept(null);
+    }
+}
+
+// FILE: Kotlin.kt
+
+
+inline fun makeRunnable(crossinline lambda: () -> Unit) =
+        object : Runnable {
+            override fun run() {
+                lambda()
+            }
+        }
+
+fun box(): String {
+    try {
+        makeRunnable {
+            J.invokeWithNull(object : J.Consumer {
+                override fun accept(t: String) {
+                    println(t)
+                }
+            })
+        }.run()
+    } catch (e: IllegalArgumentException) {
+        return "OK"
+    }
+
+    return "fail: exception expected"
+}

compiler/tests-common/org/jetbrains/kotlin/codegen/InlineTestUtil.kt

@@ -124,7 +124,7 @@ object InlineTestUtil {
                     return null
                 }
 
-                override fun visitMethod(access: Int, name: String, desc: String, signature: String, exceptions: Array<String>): MethodVisitor? {
+                override fun visitMethod(access: Int, name: String, desc: String, signature: String?, exceptions: Array<String>?): MethodVisitor? {
                     if (skipMethodsOfThisClass) {
                         return null
                     }

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxAgainstJavaCodegenTestGenerated.java

@@ -354,6 +354,21 @@ public class BlackBoxAgainstJavaCodegenTestGenerated extends AbstractBlackBoxAga
         }
     }
 
+    @TestMetadata("compiler/testData/codegen/boxAgainstJava/inline")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class Inline extends AbstractBlackBoxAgainstJavaCodegenTest {
+        public void testAllFilesPresentInInline() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/boxAgainstJava/inline"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("kt19910.kt")
+        public void testKt19910() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/boxAgainstJava/inline/kt19910.kt");
+            doTest(fileName);
+        }
+    }
+
     @TestMetadata("compiler/testData/codegen/boxAgainstJava/innerClass")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)