[ConstraintSystem] Look through specialization while simplifying constructor locator

If type is explicitly specialized i.e. `A<Int>` in certain cases its `TypeExpr`
or `OverloadedDeclRefExpr` (if type name is ambiguous) would be wrapped in
`UnresolvedSpecializeExpr` which has to be looked through when simplifying
`constructor member` so the anchor could point to the underlying type reference.

Resolves: https://github.com/apple/swift/issues/67799
Resolves: rdar://113577294

lib/Sema/ConstraintSystem.cpp

@@ -5724,6 +5724,13 @@ void constraints::simplifyLocator(ASTNode &anchor,
     }
 
     case ConstraintLocator::ConstructorMember:
+      // Look through specialization first, because it doesn't play a
+      // functional role here.
+      if (auto *USE = getAsExpr<UnresolvedSpecializeExpr>(anchor)) {
+        anchor = USE->getSubExpr();
+        range = anchor.getSourceRange();
+      }
+
       // - This is really an implicit 'init' MemberRef, so point at the base,
       //   i.e. the TypeExpr.
       // - For re-declarations we'd get an overloaded reference