Extract JVM IR backend module out of compiler/backend

The old backend does not depend on IR modules anymore

plugins/kotlin-serialization/kotlin-serialization-compiler/build.gradle.kts

@@ -1,4 +1,3 @@
-
 description = "Kotlin Serialization Compiler Plugin"
 
 plugins {
@@ -14,6 +13,7 @@ dependencies {
     compile(project(":compiler:plugin-api"))
     compile(project(":compiler:frontend"))
     compile(project(":compiler:backend"))
+    compile(project(":compiler:ir.backend.common"))
     compile(project(":js:js.frontend"))
     compile(project(":js:js.translator"))