[IR] Rename IrAnnotationsFromPluginRegistrar to IrGeneratedDeclarationsRegistrar

In further commits, this service will be used not only for registering
  annotations, but newly generated IR declarations too

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrGeneratedDeclarationsRegistrar.kt

@@ -8,7 +8,7 @@ package org.jetbrains.kotlin.backend.common.extensions
 import org.jetbrains.kotlin.ir.declarations.IrDeclaration
 import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
 
-abstract class IrAnnotationsFromPluginRegistrar {
+abstract class IrGeneratedDeclarationsRegistrar {
     abstract fun addMetadataVisibleAnnotationsToElement(declaration: IrDeclaration, annotations: List<IrConstructorCall>)
 
     fun addMetadataVisibleAnnotationsToElement(declaration: IrDeclaration, vararg annotations: IrConstructorCall) {

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrPluginContext.kt

@@ -57,10 +57,12 @@ interface IrPluginContext : IrGeneratorContext {
     val platform: TargetPlatform?
 
     /**
-     * Use this service to add annotations to declarations if those annotations should be saved into metadata
+     * Use this service to:
+     * - add annotations to declarations if those annotations should be saved into metadata
+     * - register that declaration generated at IR stage will appear in compiled metadata
      * This service properly works only in K2 compiler
      */
-    val annotationsRegistrar: IrAnnotationsFromPluginRegistrar
+    val metadataDeclarationRegistrar: IrGeneratedDeclarationsRegistrar
 
     /**
      * Returns a logger instance to post diagnostic messages from plugin

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrPluginContextImpl.kt

@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.ir.IrBuiltIns
 import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.declarations.IrConstructor
 import org.jetbrains.kotlin.ir.declarations.IrDeclaration
+import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
 import org.jetbrains.kotlin.ir.linkage.IrDeserializer
 import org.jetbrains.kotlin.ir.symbols.*
@@ -53,8 +54,8 @@ open class IrPluginContextImpl constructor(
 
     override val symbolTable: ReferenceSymbolTable = st
 
-    final override val annotationsRegistrar: IrAnnotationsFromPluginRegistrar
-        get() = DummyIrAnnotationsFromPluginRegistrar
+    final override val metadataDeclarationRegistrar: IrGeneratedDeclarationsRegistrar
+        get() = DummyIrGeneratedDeclarationsRegistrar
 
     private fun resolveMemberScope(fqName: FqName): MemberScope? {
         val pkg = module.getPackage(fqName)
@@ -181,7 +182,7 @@ open class IrPluginContextImpl constructor(
         return symbol
     }
 
-    private object DummyIrAnnotationsFromPluginRegistrar : IrAnnotationsFromPluginRegistrar() {
+    private object DummyIrGeneratedDeclarationsRegistrar : IrGeneratedDeclarationsRegistrar() {
         override fun addMetadataVisibleAnnotationsToElement(declaration: IrDeclaration, annotations: List<IrConstructorCall>) {
             declaration.annotations += annotations
         }