JVM IR: fix containing declaration for top level members in wrapped descriptors

In addition to fixing getContainingDeclaration, change origin of
multifile facades to FILE_CLASS since the corresponding class descriptor
should also be skipped when computing containing declaration. This fixes
the problem with internal function calls in -Xmultifile-parts-inherit
mode (previously we incorrectly mangled the function name in
MethodSignatureMapper), and also fixes coroutine intrinsic calls when
compiling kotlin-stdlib with JVM IR. In the latter case, all intrinsics
(such as isBuiltInSuspendCoroutineUninterceptedOrReturn) are present in
sources, and were previously not detected as intrinsics by the code in
`generateInlineIntrinsic` because the FQ name didn't match: it had an
additional component for the file class name.

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -16517,6 +16517,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 runTest("compiler/testData/codegen/box/multifileClasses/optimized/calls.kt");
             }
 
+            @TestMetadata("internalFunction.kt")
+            public void testInternalFunction() throws Exception {
+                runTest("compiler/testData/codegen/box/multifileClasses/optimized/internalFunction.kt");
+            }
+
             @TestMetadata("overlappingFuns.kt")
             public void testOverlappingFuns() throws Exception {
                 runTest("compiler/testData/codegen/box/multifileClasses/optimized/overlappingFuns.kt");