JVM_IR: Support init blocks in inline classes

Put their content to constructor-impl, so they are called during
constructor call, but they are not called during boxing, because
box-impl calls <init> and not constructor-impl.

 #KT-28055 In progress

compiler/testData/codegen/box/inlineClasses/boxImplDoesNotExecuteInitBlock.kt

@@ -0,0 +1,24 @@
+// IGNORE_BACKEND: JVM
+// IGNORE_BACKEND: JS_IR
+// IGNORE_LIGHT_ANALYSIS
+
+inline class IC(val i: Int) {
+    init {
+        counter += i
+    }
+}
+
+var counter = 0
+
+fun <T> id(t: T) = t
+
+fun box(): String {
+    val ic = IC(42)
+    if (counter != 42) return "FAIL 1: $counter"
+    counter = 0
+
+    id(ic)
+    if (counter != 0) return "FAIL 2: $counter"
+
+    return "OK"
+}