[Diagnostics] Add a tailored fix when ternary is associated with return

If it has been detected that there is an attempt to return a value
from a function without result type, let's diagnose that specifically
in cases when ternary operator is involved.

lib/Sema/CSSimplify.cpp

@@ -4224,6 +4224,12 @@ bool ConstraintSystem::repairFailures(
         if (hasFixFor(loc, FixKind::ContextualMismatch))
           return true;
 
+        if (contextualType->isVoid() &&
+            getContextualTypePurpose(anchor) == CTP_ReturnStmt) {
+          conversionsOrFixes.push_back(RemoveReturn::create(*this, lhs, loc));
+          break;
+        }
+
         conversionsOrFixes.push_back(
             ContextualMismatch::create(*this, lhs, rhs, loc));
         break;