[move-only] Validate in the SILVerifier that we only have copy_addr [init]/load [copy] on move only values in Raw SIL.

This is already an invariant for copy_value and now that I am implementing move
semantics for addresses, it makes sense to ban those in a similar
way. Specifically, we are enforcing the invariant that move only types are
allowed to be copied in Raw SIL, but not in later parts of SIL. For those who
are unaware, we then run checkers later to validate that we preserve ownership
semantics.

Author: gottesmm

lib/SIL/Verifier/SILVerifier.cpp

@@ -2189,6 +2189,10 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
               "Load with unqualified ownership in a qualified function");
       break;
     case LoadOwnershipQualifier::Copy:
+      require(LI->getModule().getStage() == SILStage::Raw ||
+                  !LI->getOperand()->getType().isMoveOnly(),
+              "'MoveOnly' types can only be copied in Raw SIL?!");
+      [[fallthrough]];
     case LoadOwnershipQualifier::Take:
       require(F.hasOwnership(),
               "Load with qualified ownership in an unqualified function");
@@ -2655,15 +2659,17 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
       require(Elt->getType().isAddress(), "MFE must refer to variable addrs");
   }
 
-  void checkCopyAddrInst(CopyAddrInst *SI) {
-    require(SI->getSrc()->getType().isAddress(),
-            "Src value should be lvalue");
-    require(SI->getDest()->getType().isAddress(),
+  void checkCopyAddrInst(CopyAddrInst *cai) {
+    require(cai->getSrc()->getType().isAddress(), "Src value should be lvalue");
+    require(cai->getDest()->getType().isAddress(),
             "Dest address should be lvalue");
-    requireSameType(SI->getDest()->getType(), SI->getSrc()->getType(),
+    requireSameType(cai->getDest()->getType(), cai->getSrc()->getType(),
                     "Store operand type and dest type mismatch");
-    require(F.isTypeABIAccessible(SI->getDest()->getType()),
+    require(F.isTypeABIAccessible(cai->getDest()->getType()),
             "cannot directly copy type with inaccessible ABI");
+    require(cai->getModule().getStage() == SILStage::Raw ||
+                (cai->isTakeOfSrc() || !cai->getSrc()->getType().isMoveOnly()),
+            "'MoveOnly' types can only be copied in Raw SIL?!");
   }
 
   void checkMarkUnresolvedMoveAddrInst(MarkUnresolvedMoveAddrInst *SI) {