Make stdlib work with -Xmultifile-package-facades.

Fixed wrong owner mapping in presence of -Xmultifile-package-facades.
Fixed backing field mapping issue.
Added more tests.

compiler/testData/codegen/bytecodeTextMultifile/partMembersInline/otherFile.kt

@@ -0,0 +1,4 @@
+@file:[JvmName("Util") JvmMultifileClass]
+package test
+
+public fun publicInOtherFile() {}

compiler/testData/codegen/bytecodeTextMultifile/partMembersInline/thisFile.kt

@@ -0,0 +1,18 @@
+@file:[JvmName("Util") JvmMultifileClass]
+package test
+
+inline fun foo(body: () -> Unit) {
+    publicInThisFile()
+    publicInOtherFile()
+    body()
+}
+
+public fun publicInThisFile() {}
+
+fun bar() {
+    foo {}
+}
+
+// @test/Util__ThisFileKt.class:
+// 2 INVOKESTATIC test/Util.publicInThisFile
+// 2 INVOKESTATIC test/Util.publicInOtherFile