JVM IR: remove dependency of 'backend.jvm' on 'psi2ir', 'ir.serialization.jvm'

Add a new module 'backend.jvm.entrypoint' which depends on psi2ir and
contains code that runs psi2ir + JVM IR backend with serialization
implementations.

Hopefully this will allow to compile these modules in parallel and
reduce the build time.

idea/build.gradle.kts

@@ -86,6 +86,7 @@ dependencies {
     compile(project(":kotlin-script-util")) { isTransitive = false }
     compile(project(":kotlin-scripting-intellij"))
     compile(project(":compiler:backend.jvm")) // Do not delete, for Pill
+    compile(project(":compiler:backend.jvm:backend.jvm.entrypoint"))
 
     compile(commonDep("org.jetbrains.kotlinx", "kotlinx-coroutines-core")) { isTransitive = false }