[move-only] When we emit a noncopyable temporary allocation, always attach a mark_must_check [consumable_and_assignable].

Most of the time SILGen already emits these correctly without having extra
copies, but in certain situations SILGen will emit copies that we need the move
checker to eliminate (e.x.: when we generate a yield). An additional benefit is
that this also will catch places where the frontend makes a mistake.

This also removes a bunch of "copy of noncopyable" types error that showed up in
the implicit compiler generated modify.

Author: gottesmm

lib/SILGen/SILGenDecl.cpp

@@ -1964,13 +1964,19 @@ InitializationPtr SILGenFunction::emitLocalVariableWithCleanup(
 std::unique_ptr<TemporaryInitialization>
 SILGenFunction::emitTemporary(SILLocation loc, const TypeLowering &tempTL) {
   SILValue addr = emitTemporaryAllocation(loc, tempTL.getLoweredType());
+  if (addr->getType().isMoveOnly())
+    addr = B.createMarkMustCheckInst(
+        loc, addr, MarkMustCheckInst::CheckKind::ConsumableAndAssignable);
   return useBufferAsTemporary(addr, tempTL);
 }
 
 std::unique_ptr<TemporaryInitialization>
 SILGenFunction::emitFormalAccessTemporary(SILLocation loc,
                                           const TypeLowering &tempTL) {
   SILValue addr = emitTemporaryAllocation(loc, tempTL.getLoweredType());
+  if (addr->getType().isMoveOnly())
+    addr = B.createMarkMustCheckInst(
+        loc, addr, MarkMustCheckInst::CheckKind::ConsumableAndAssignable);
   CleanupHandle cleanup =
       enterDormantFormalAccessTemporaryCleanup(addr, loc, tempTL);
   return std::unique_ptr<TemporaryInitialization>(

lib/SILGen/SILGenLValue.cpp

@@ -366,6 +366,7 @@ LogicalPathComponent::projectForRead(SILGenFunction &SGF, SILLocation loc,
   }
 
   TemporaryInitializationPtr tempInit;
+  ManagedValue result;
   RValue rvalue;
 
   // If the RValue type has an openedExistential, then the RValue must be
@@ -377,9 +378,11 @@ LogicalPathComponent::projectForRead(SILGenFunction &SGF, SILLocation loc,
 
     // Create a temporary, whose type may depend on the 'get'.
     tempInit = SGF.emitFormalAccessTemporary(loc, RValueTL);
+    result = tempInit->getManagedAddress();
   } else {
     // Create a temporary for a static (non-dependent) RValue type.
     tempInit = SGF.emitFormalAccessTemporary(loc, RValueTL);
+    result = tempInit->getManagedAddress();
 
     // Emit a 'get' directly into the temporary.
     rvalue = std::move(*this).get(SGF, loc, base, SGFContext(tempInit.get()));
@@ -390,7 +393,8 @@ LogicalPathComponent::projectForRead(SILGenFunction &SGF, SILLocation loc,
   if (!rvalue.isInContext())
     std::move(rvalue).forwardInto(SGF, loc, tempInit.get());
 
-  return tempInit->getManagedAddress();
+  assert(result);
+  return result;
 }
 
 ManagedValue LogicalPathComponent::project(SILGenFunction &SGF,