[NCGenerics] fix a few isNoncopyable calls

These calls were being made on types either with a type parameter, or a
SIL-only type that doesn't actually have conformances.

In such cases, it's better to use SILType's move-only query methods.

Author: kavon

include/swift/AST/Types.h

@@ -5539,7 +5539,9 @@ class SILMoveOnlyWrappedType final : public TypeBase,
       : TypeBase(TypeKind::SILMoveOnlyWrapped, &innerType->getASTContext(),
                  innerType->getRecursiveProperties()),
         innerType(innerType) {
-    assert(!innerType->isNoncopyable() && "Inner type must be copyable");
+    // If it has a type parameter, we can't check whether it's copyable.
+    assert(innerType->hasTypeParameter() ||
+           !innerType->isNoncopyable() && "Inner type must be copyable");
   }
 
 public:

lib/SIL/IR/SILType.cpp

@@ -1062,6 +1062,7 @@ bool SILType::isMoveOnly() const {
   auto ty = getASTType();
 
   // All kinds of references are copyable.
+  // FIXME: this doesn't match with how isNoncopyable in the AST handles it!
   if (isa<ReferenceStorageType>(ty))
     return false;
 

lib/SILOptimizer/Utils/InstructionDeleter.cpp

@@ -71,7 +71,8 @@ static bool isScopeAffectingInstructionDead(SILInstruction *inst,
     // getSingleValueCopyOrCast returns true.  That function returns true for
     // move_value instructions.  And `move_value %moveOnlyValue` must not be
     // deleted.
-    if (result->getType().getASTType()->isNoncopyable() &&
+    auto type = result->getType();
+    if (type.isMoveOnly() && !type.isMoveOnlyWrapped() &&
         result->getOwnershipKind() == OwnershipKind::Owned) {
       return false;
     }