[FIR JS] KT-57601: Get rid of the builtin provider

In this example we get 2 variants of `kotlin/toString()`:
one coming from the KLib provider, and the
other coming from the builtins provider.
These are identical deserialized functions.

^KT-57601 Fixed

compiler/testData/diagnostics/testsWithJsStdLib/jvmDeclarations/cloneable.fir.kt

@@ -1,3 +1,3 @@
-import kotlin.Cloneable
+import kotlin.<!UNRESOLVED_IMPORT!>Cloneable<!>
 
-fun cloneable(): Cloneable = intArrayOf(42)
+fun cloneable(): <!UNRESOLVED_REFERENCE!>Cloneable<!> = intArrayOf(42)