Add ClassDescriptor.getInlineClassRepresentation

This will be used at least in the JVM backend instead of the current
approach where we're loading the primary constructor's first parameter,
which isn't good enough since primary constructor can be private, and
we can't rely on private declarations in case they're declared in
another module.

compiler/testData/codegen/box/compileKotlinAgainstKotlin/inlineClasses/extensionPropertyWithSameName.kt

@@ -0,0 +1,14 @@
+// WITH_RUNTIME
+// MODULE: lib
+// FILE: A.kt
+
+inline class A(val value: String) {
+    val Char.value: String get() = this + nonExtensionValue()
+
+    fun nonExtensionValue(): String = value
+}
+
+// MODULE: main(lib)
+// FILE: B.kt
+
+fun box(): String = with(A("K")) { 'O'.value }

compiler/testData/codegen/box/compileKotlinAgainstKotlin/inlineClasses/oldMangling/extensionPropertyWithSameName.kt

@@ -0,0 +1,16 @@
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+// MODULE: lib
+// USE_OLD_INLINE_CLASSES_MANGLING_SCHEME
+// FILE: A.kt
+
+inline class A(val value: String) {
+    val Char.value: String get() = this + nonExtensionValue()
+
+    fun nonExtensionValue(): String = value
+}
+
+// MODULE: main(lib)
+// FILE: B.kt
+
+fun box(): String = with(A("K")) { 'O'.value }