Move default implementation of TargetPlatform.platformName to leaf classes

Otherwise, we have a static initialization loop, leading to null-leaks

Removing default interface method indeed disconnects the loop, as per JVM
Specification, "5.5 Initialization".

See KT-33245 for detailed explanations

^KT-33245 Fixed

compiler/cli/cli-common/src/org/jetbrains/kotlin/analyzer/common/CommonPlatform.kt

@@ -16,10 +16,6 @@ import org.jetbrains.kotlin.resolve.TargetPlatform
     level = DeprecationLevel.ERROR
 )
 interface CommonPlatform : TargetPlatform {
-    @JvmDefault
-    override val platformName: String
-        get() = "Default"
-
     companion object {
         @JvmField
         val INSTANCE: CommonPlatform = CommonPlatforms.CompatCommonPlatform

compiler/cli/cli-common/src/org/jetbrains/kotlin/platform/CommonPlatforms.kt

@@ -25,7 +25,10 @@ object CommonPlatforms {
             defaultJsPlatform.single(),
             defaultKonanPlatform.single()
         )
-    ), org.jetbrains.kotlin.analyzer.common.CommonPlatform
+    ), org.jetbrains.kotlin.analyzer.common.CommonPlatform {
+        override val platformName: String
+            get() = "Default"
+    }
 
     val defaultCommonPlatform: TargetPlatform
         get() = CompatCommonPlatform

compiler/cli/cli-common/src/org/jetbrains/kotlin/platform/konan/KonanPlatform.kt

@@ -24,7 +24,10 @@ object KonanPlatforms {
     )
     object CompatKonanPlatform : TargetPlatform(setOf(DefaultSimpleKonanPlatform)),
         // Needed for backward compatibility, because old code uses INSTANCEOF checks instead of calling extensions
-        org.jetbrains.kotlin.resolve.konan.platform.KonanPlatform {}
+        org.jetbrains.kotlin.resolve.konan.platform.KonanPlatform {
+        override val platformName: String
+            get() = "Native"
+    }
 
     val defaultKonanPlatform: TargetPlatform
         get() = CompatKonanPlatform

compiler/cli/cli-common/src/org/jetbrains/kotlin/resolve/konan/platform/KonanPlatform.kt

@@ -16,10 +16,6 @@ import org.jetbrains.kotlin.resolve.TargetPlatform
     level = DeprecationLevel.ERROR
 )
 interface KonanPlatform : TargetPlatform {
-    @JvmDefault
-    override val platformName: String
-        get() = "Native"
-
     companion object {
         @JvmField
         val INSTANCE: KonanPlatform = KonanPlatforms.CompatKonanPlatform