FIR2IR: Rework resulted overridden-relation structure

The difference is how we deal with intermediate fake overrides
E.g., in case

interface A { /* $1 */ fun foo() }
interface B : A {
     /* $2 */ fake_override fun foo()
}
interface C : B {
   /* $3 */ override fun foo()
}

We've got FIR declarations only for $1 and $3, but we've got
a fake override for $2 in IR.

Previously, override $3 had $1 as its overridden IR symbol, just because
FIR declaration of $3 doesn't know anything about $2.

Now, when generating IR for $2, we save the necessary information
and using it for $3, so it has $2 as overridden.

So, it's consistent with the overridden structure of FE 1.0 and this
structure is necessary prerequisite for proper building of bridges
for special built-ins.

compiler/testData/codegen/box/builtinStubMethods/extendJavaCollections/abstractMap.kt

@@ -1,6 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
 // WASM_MUTE_REASON: STDLIB_COLLECTIONS
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 
 import java.util.AbstractMap

compiler/testData/codegen/box/builtinStubMethods/extendJavaCollections/abstractSet.kt

@@ -1,6 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
 // WASM_MUTE_REASON: STDLIB_COLLECTIONS
-// IGNORE_BACKEND_FIR: JVM_IR
 // KJS_WITH_FULL_RUNTIME
 // IGNORE_BACKEND: NATIVE
 class A : HashSet<Long>()

compiler/testData/codegen/box/builtinStubMethods/extendJavaCollections/hashMap.kt

@@ -1,6 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
 // WASM_MUTE_REASON: STDLIB_COLLECTIONS
-// IGNORE_BACKEND_FIR: JVM_IR
 // KJS_WITH_FULL_RUNTIME
 // IGNORE_BACKEND: NATIVE
 class A : HashMap<String, Double>()

compiler/testData/codegen/box/builtinStubMethods/extendJavaCollections/hashSet.kt

@@ -1,6 +1,5 @@
 // DONT_TARGET_EXACT_BACKEND: WASM
 // WASM_MUTE_REASON: STDLIB_COLLECTIONS
-// IGNORE_BACKEND_FIR: JVM_IR
 // KJS_WITH_FULL_RUNTIME
 // IGNORE_BACKEND: NATIVE
 class A : HashSet<Long>()