FIR2IR: Rework fake overrides generation

- To discriminate what's already been generated, use the set of declaration
instead of names (it's obviously more correct)
- Make it possible to set more then one overridden (base)

compiler/testData/ir/irText/declarations/annotations/enumEntriesWithAnnotations.fir.txt

@@ -67,10 +67,10 @@ FILE fqName:<root> fileName:/enumEntriesWithAnnotations.kt
           overridden:
             protected final fun clone (): kotlin.Any declared in kotlin.Enum
           $this: VALUE_PARAMETER name:<this> type:kotlin.Enum<E of kotlin.Enum>
-        FUN FAKE_OVERRIDE name:compareTo visibility:public modality:FINAL <> ($this:<root>.TestEnum, other:<root>.TestEnum) returnType:kotlin.Int [fake_override,operator]
+        FUN FAKE_OVERRIDE name:compareTo visibility:public modality:FINAL <> ($this:kotlin.Enum<E of kotlin.Enum>, other:<root>.TestEnum) returnType:kotlin.Int [fake_override,operator]
           overridden:
             public final fun compareTo (other: E of kotlin.Enum): kotlin.Int [operator] declared in kotlin.Enum
-          $this: VALUE_PARAMETER name:<this> type:<root>.TestEnum
+          $this: VALUE_PARAMETER name:<this> type:kotlin.Enum<E of kotlin.Enum>
           VALUE_PARAMETER name:other index:0 type:<root>.TestEnum
         FUN FAKE_OVERRIDE name:equals visibility:public modality:FINAL <> ($this:kotlin.Enum<E of kotlin.Enum>, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
           overridden:

compiler/testData/ir/irText/declarations/fakeOverrides.fir.txt

@@ -83,6 +83,7 @@ FILE fqName:<root> fileName:/fakeOverrides.kt
     FUN FAKE_OVERRIDE name:foo visibility:public modality:FINAL <> ($this:<root>.CFoo<T of <root>.CFoo>, x:kotlin.String) returnType:kotlin.Unit [fake_override]
       overridden:
         public final fun foo (x: T of <root>.CFoo): kotlin.Unit declared in <root>.CFoo
+        public abstract fun foo (x: kotlin.String): kotlin.Unit declared in <root>.IFooStr
       $this: VALUE_PARAMETER name:<this> type:<root>.CFoo<T of <root>.CFoo>
       VALUE_PARAMETER name:x index:0 type:kotlin.String
     FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]

compiler/testData/ir/irText/declarations/multiplatform/expectClassInherited.fir.txt

@@ -4,7 +4,7 @@ FILE fqName:<root> fileName:/expectClassInherited.kt
     CONSTRUCTOR visibility:protected <> () returnType:<root>.A [primary,expect]
     FUN name:foo visibility:public modality:ABSTRACT <> ($this:<root>.A) returnType:kotlin.Unit [expect]
       $this: VALUE_PARAMETER name:<this> type:<root>.A
-    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [expect,fake_override]
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [expect,fake_override,operator]
       overridden:
         public open fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Any
       $this: VALUE_PARAMETER name:<this> type:kotlin.Any
@@ -28,7 +28,7 @@ FILE fqName:<root> fileName:/expectClassInherited.kt
     FUN name:bar visibility:public modality:OPEN <> ($this:<root>.B, s:kotlin.String) returnType:kotlin.Unit [expect]
       $this: VALUE_PARAMETER name:<this> type:<root>.B
       VALUE_PARAMETER name:s index:0 type:kotlin.String
-    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [expect,fake_override]
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [expect,fake_override,operator]
       overridden:
         public open fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Any
       $this: VALUE_PARAMETER name:<this> type:kotlin.Any

compiler/testData/ir/irText/declarations/multiplatform/expectedEnumClass.fir.txt

@@ -15,12 +15,12 @@ FILE fqName:<root> fileName:/expectedEnumClass.kt
       overridden:
         protected final fun clone (): kotlin.Any declared in kotlin.Enum
       $this: VALUE_PARAMETER name:<this> type:kotlin.Enum<E of kotlin.Enum>
-    FUN FAKE_OVERRIDE name:compareTo visibility:public modality:FINAL <> ($this:kotlin.Enum<E of kotlin.Enum>, other:<root>.MyEnum) returnType:kotlin.Int [expect,fake_override]
+    FUN FAKE_OVERRIDE name:compareTo visibility:public modality:FINAL <> ($this:kotlin.Enum<E of kotlin.Enum>, other:<root>.MyEnum) returnType:kotlin.Int [expect,fake_override,operator]
       overridden:
         public final fun compareTo (other: E of kotlin.Enum): kotlin.Int [operator] declared in kotlin.Enum
       $this: VALUE_PARAMETER name:<this> type:kotlin.Enum<E of kotlin.Enum>
       VALUE_PARAMETER name:other index:0 type:<root>.MyEnum
-    FUN FAKE_OVERRIDE name:equals visibility:public modality:FINAL <> ($this:kotlin.Enum<E of kotlin.Enum>, other:kotlin.Any?) returnType:kotlin.Boolean [expect,fake_override]
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:FINAL <> ($this:kotlin.Enum<E of kotlin.Enum>, other:kotlin.Any?) returnType:kotlin.Boolean [expect,fake_override,operator]
       overridden:
         public final fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Enum
       $this: VALUE_PARAMETER name:<this> type:kotlin.Enum<E of kotlin.Enum>

compiler/testData/ir/irText/declarations/multiplatform/expectedSealedClass.fir.txt

@@ -2,7 +2,7 @@ FILE fqName:<root> fileName:/expectedSealedClass.kt
   CLASS CLASS name:Ops modality:SEALED visibility:public [expect] superTypes:[kotlin.Any]
     $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.Ops
     CONSTRUCTOR visibility:private <> () returnType:<root>.Ops [primary,expect]
-    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [expect,fake_override]
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [expect,fake_override,operator]
       overridden:
         public open fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Any
       $this: VALUE_PARAMETER name:<this> type:kotlin.Any
@@ -18,7 +18,7 @@ FILE fqName:<root> fileName:/expectedSealedClass.kt
   CLASS CLASS name:Add modality:FINAL visibility:public [expect] superTypes:[<root>.Ops]
     $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.Add
     CONSTRUCTOR visibility:public <> () returnType:<root>.Add [primary,expect]
-    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [expect,fake_override]
+    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [expect,fake_override,operator]
       overridden:
         public open fun equals (other: kotlin.Any?): kotlin.Boolean [operator] declared in kotlin.Any
       $this: VALUE_PARAMETER name:<this> type:kotlin.Any