Add test for VAL_REASSIGNMENT on when subject variable

compiler/testData/diagnostics/tests/when/withSubjectVariable/reassignmentToWhenSubjectVariable.kt

@@ -0,0 +1,10 @@
+// !LANGUAGE: +VariableDeclarationInWhenSubject
+// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER -UNUSED_VALUE
+
+fun foo(): Any = 42
+
+fun test(x: Any) {
+    when (val y = foo()) {
+        is String -> <!VAL_REASSIGNMENT!>y<!> = ""
+    }
+}

compiler/testData/diagnostics/tests/when/withSubjectVariable/reassignmentToWhenSubjectVariable.txt

@@ -0,0 +1,4 @@
+package
+
+public fun foo(): kotlin.Any
+public fun test(/*0*/ x: kotlin.Any): kotlin.Unit

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -22472,6 +22472,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("reassignmentToWhenSubjectVariable.kt")
+                public void testReassignmentToWhenSubjectVariable() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/when/withSubjectVariable/reassignmentToWhenSubjectVariable.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("shadowingOtherVariable.kt")
                 public void testShadowingOtherVariable() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/when/withSubjectVariable/shadowingOtherVariable.kt");

compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java

@@ -22472,6 +22472,12 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                     doTest(fileName);
                 }
 
+                @TestMetadata("reassignmentToWhenSubjectVariable.kt")
+                public void testReassignmentToWhenSubjectVariable() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/when/withSubjectVariable/reassignmentToWhenSubjectVariable.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("shadowingOtherVariable.kt")
                 public void testShadowingOtherVariable() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/when/withSubjectVariable/shadowingOtherVariable.kt");