[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/nestedClassConstructorVsMemberFunctionConflict.kt

@@ -0,0 +1,10 @@
+// FIR_IDENTICAL
+// ISSUE: KT-62005
+
+class A {
+    class NestedInA<!CONFLICTING_OVERLOADS!>()<!>
+    <!CONFLICTING_OVERLOADS!>fun NestedInA()<!> {}
+
+    class <!CONFLICTING_OVERLOADS!>NestedInA2<!>
+    <!CONFLICTING_OVERLOADS!>fun NestedInA2()<!> {}
+}