Prohibit platformName on secondary constructor

#KT-6999 Fixed

compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.java

@@ -295,7 +295,8 @@ public class ModifiersChecker {
         JetAnnotationEntry annotationEntry = trace.get(BindingContext.ANNOTATION_DESCRIPTOR_TO_PSI_ELEMENT, annotation);
         if (annotationEntry == null) return;
 
-        if (!DescriptorUtils.isTopLevelDeclaration(descriptor) || !(descriptor instanceof FunctionDescriptor)) {
+        if (!DescriptorUtils.isTopLevelDeclaration(descriptor) || !(descriptor instanceof FunctionDescriptor) ||
+            descriptor instanceof ConstructorDescriptor) {
             trace.report(INAPPLICABLE_ANNOTATION.on(annotationEntry));
         }
 

compiler/testData/diagnostics/testsWithStdLib/annotations/annotationApplicability/platformName.kt

@@ -1,4 +1,4 @@
-// !DIAGNOSTICS: -UNUSED_VARIABLE
+// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
 
 import kotlin.platform.*
 
@@ -32,7 +32,8 @@ var vardef: Int = 1
     set
 
 [<!INAPPLICABLE_ANNOTATION!>platformName("C")<!>]
-class C {
+class C [platformName("primary")]() { // TODO: modifiers check on primary constructor KT-7057
+    <!INAPPLICABLE_ANNOTATION!>platformName("ctr")<!> constructor(x: Int): this() {}
     [<!INAPPLICABLE_ANNOTATION!>platformName("a")<!>]
     fun foo() {}
 

compiler/testData/diagnostics/testsWithStdLib/annotations/annotationApplicability/platformName.txt

@@ -10,7 +10,8 @@ internal fun foo1(): kotlin.Unit
 kotlin.platform.platformName(name = "b": kotlin.String) internal fun kotlin.Any.foo(): kotlin.Unit
 
 kotlin.platform.platformName(name = "C": kotlin.String) internal final class C {
-    public constructor C()
+    kotlin.platform.platformName(name = "primary": kotlin.String) public constructor C()
+    kotlin.platform.platformName(name = "ctr": kotlin.String) public constructor C(/*0*/ x: kotlin.Int)
     kotlin.platform.platformName(name = "c": kotlin.String) internal final val px: kotlin.Int = 1
     internal final val valx: kotlin.Int
     internal final var varx: kotlin.Int