[FIR] Check conflicts between nested classes' constructors and member functions

For an example of an object with
an implicit primary constructor,
see `FirPsiOldFrontendDiagnosticsTestGenerated.testSingletonAndFunctionSameName`.

^KT-62005 Fixed


Merge-request: KT-MR-12242
Merged-by: Nikolay Lunyak <Nikolay.Lunyak@jetbrains.com>

compiler/testData/diagnostics/tests/overload/ConstructorVsFunOverload.fir.kt

@@ -15,16 +15,16 @@ class a<!CONFLICTING_OVERLOADS!>()<!> { }
 <!CONFLICTING_OVERLOADS!>fun a()<!> = 1
 
 class Tram {
-    fun f() { }
+    <!CONFLICTING_OVERLOADS!>fun f()<!> { }
 
-    class f() { }
+    class f<!CONFLICTING_OVERLOADS!>()<!> { }
 }
 
 class Yvayva {
     companion object {
-        fun fghj() { }
+        <!CONFLICTING_OVERLOADS!>fun fghj()<!> { }
 
-        class fghj() { }
+        class fghj<!CONFLICTING_OVERLOADS!>()<!> { }
     }
 }