Don't generate backing field for erased inline class

compiler/testData/codegen/bytecodeListing/inlineClasses/shapeOfInlineClassWithPrimitive.kt

@@ -0,0 +1,7 @@
+// !LANGUAGE: +InlineClasses
+
+inline class Foo(val l: Long) {
+    fun empty() {}
+    fun param(x: Double) {}
+    fun Any.extension(y: String) {}
+}

compiler/testData/codegen/bytecodeListing/inlineClasses/shapeOfInlineClassWithPrimitive.txt

@@ -0,0 +1,16 @@
+@kotlin.Metadata
+public final static class Foo$Erased {
+    public final static method empty(p0: long): void
+    public final static method extension(p0: long, @org.jetbrains.annotations.NotNull p1: java.lang.Object, @org.jetbrains.annotations.NotNull p2: java.lang.String): void
+    public final static method param(p0: long, p1: double): void
+}
+
+@kotlin.Metadata
+public final class Foo {
+    private final field l: long
+    public method <init>(p0: long): void
+    public final method empty(): void
+    public final method extension(@org.jetbrains.annotations.NotNull p0: java.lang.Object, @org.jetbrains.annotations.NotNull p1: java.lang.String): void
+    public final method getL(): long
+    public final method param(p0: double): void
+}