Unused symbol: fix false positives on inline class constructors

#KT-27434 Fixed

idea/src/org/jetbrains/kotlin/idea/inspections/UnusedSymbolInspection.kt

@@ -327,11 +327,10 @@ class UnusedSymbolInspection : AbstractKotlinInspection() {
     private fun KtCallableDeclaration.canBeHandledByLightMethods(descriptor: DeclarationDescriptor?): Boolean {
         return when {
             hasModifier(KtTokens.INTERNAL_KEYWORD) -> false
-            this !is KtNamedFunction -> true
             descriptor !is FunctionDescriptor -> true
+            descriptor is ConstructorDescriptor -> !descriptor.constructedClass.isInline
             else -> !descriptor.hasInlineClassParameters()
         }
-
     }
 
     private fun FunctionDescriptor.hasInlineClassParameters(): Boolean {

idea/testData/inspectionsLocal/unusedSymbol/inlineClassConstructor.kt

@@ -0,0 +1,7 @@
+// PROBLEM: none
+
+inline class InlineClass(val x: Int) {
+    <caret>constructor() : this(42)
+}
+
+val call = InlineClass()

idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java

@@ -6613,6 +6613,11 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             runTest("idea/testData/inspectionsLocal/unusedSymbol/inAnonymousRunWrapped.kt");
         }
 
+        @TestMetadata("inlineClassConstructor.kt")
+        public void testInlineClassConstructor() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedSymbol/inlineClassConstructor.kt");
+        }
+
         @TestMetadata("inlineClassMemberFunction.kt")
         public void testInlineClassMemberFunction() throws Exception {
             runTest("idea/testData/inspectionsLocal/unusedSymbol/inlineClassMemberFunction.kt");