Some fixes wrt generic coroutines

Author: asl

lib/SIL/IR/SILFunctionType.cpp

@@ -2412,9 +2412,10 @@ static CanSILFunctionType getSILFunctionType(
     }
   } else if (substFnInterfaceType->isCoroutine()) { // Derive yield type for function type
     coroutineKind = SILCoroutineKind::YieldOnce;
+    auto sig = origType.hasGenericSignature() ? origType.getGenericSignature() : genericSig;
     auto origYieldType = origType.getFunctionResultType().getType()->castTo<YieldResultType>();
-    auto reducedYieldType = genericSig.getReducedType(origYieldType->getResultType());
-    coroutineOrigYieldType = AbstractionPattern(genericSig, reducedYieldType);
+    auto reducedYieldType = sig.getReducedType(origYieldType->getResultType());
+    coroutineOrigYieldType = AbstractionPattern(sig, reducedYieldType);
 
     auto yieldType = substFnInterfaceType->getResult()->castTo<YieldResultType>();
     auto valueType = yieldType->getResultType();

lib/Sema/TypeCheckType.cpp

@@ -5689,6 +5689,7 @@ NeverNullType TypeResolver::resolveTupleType(TupleTypeRepr *repr,
         inStage(TypeResolutionStage::Interface) &&
         !moveOnlyElementIndex.has_value() &&
         !ty->hasUnboundGenericType() &&
+        !ty->is<YieldResultType>() &&
         !isa<TupleTypeRepr>(tyR)) {
       auto contextTy = GenericEnvironment::mapTypeIntoContext(
           resolution.getGenericSignature().getGenericEnvironment(), ty);