Prohibit initializer blocks inside inline classes

compiler/testData/diagnostics/tests/inlineClasses/presenceOfInitializerBlockInsideInlineClass.kt

@@ -0,0 +1,10 @@
+// !LANGUAGE: +InlineClasses
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+
+inline class Foo(val x: Int) {
+    <!INLINE_CLASS_WITH_INITIALIZER!>init<!> {}
+
+    <!INLINE_CLASS_WITH_INITIALIZER!>init<!> {
+        val f = 1
+    }
+}

compiler/testData/diagnostics/tests/inlineClasses/presenceOfInitializerBlockInsideInlineClass.txt

@@ -0,0 +1,9 @@
+package
+
+public final inline class Foo {
+    public constructor Foo(/*0*/ x: kotlin.Int)
+    public final val x: kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}