IR: extract StaticInitializersLowering out of InitializersLowering

And use it in JVM backend only. Also remove unneeded
`patchDeclarationParents` call.

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/DeclarationOrigins.kt

@@ -10,9 +10,8 @@ import org.jetbrains.kotlin.ir.declarations.IrDeclarationOriginImpl
 import org.jetbrains.kotlin.ir.expressions.IrStatementOriginImpl
 
 object JsLoweredDeclarationOrigin : IrDeclarationOrigin {
-    object CLASS_STATIC_INITIALIZER : IrDeclarationOriginImpl("CLASS_STATIC_INITIALIZER")
     object JS_INTRINSICS_STUB : IrDeclarationOriginImpl("JS_INTRINSICS_STUB")
     object JS_CLOSURE_BOX_CLASS : IrStatementOriginImpl("JS_CLOSURE_BOX_CLASS")
     object JS_CLOSURE_BOX_CLASS_DECLARATION : IrDeclarationOriginImpl("JS_CLOSURE_BOX_CLASS_DECLARATION")
     object BRIDGE_TO_EXTERNAL_FUNCTION : IrDeclarationOriginImpl("BRIDGE_TO_EXTERNAL_FUNCTION")
-}
+}

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsLoweringPhases.kt

@@ -258,8 +258,8 @@ private val primaryConstructorLoweringPhase = makeJsModulePhase(
     prerequisite = setOf(enumClassConstructorLoweringPhase)
 )
 
-private val initializersLoweringPhase = makeCustomJsModulePhase(
-    { context, module -> InitializersLowering(context, JsLoweredDeclarationOrigin.CLASS_STATIC_INITIALIZER, false).lower(module) },
+private val initializersLoweringPhase = makeJsModulePhase(
+    ::InitializersLowering,
     name = "InitializersLowering",
     description = "Merge init block and field initializers into [primary] constructor",
     prerequisite = setOf(enumClassConstructorLoweringPhase, primaryConstructorLoweringPhase)