[SIL-opaque] avoid handling operands past 64k

Author: atrick

lib/SILOptimizer/Mandatory/AddressLowering.cpp

@@ -840,7 +840,11 @@ void ValueStorageMap::recordComposingUseProjection(Operand *oper,
   auto &storage = getStorage(oper->get());
   assert(!storage.isAllocated());
   storage.projectedStorageID = getOrdinal(userValue);
+
   storage.projectedOperandNum = oper->getOperandNumber();
+  assert(storage.projectedOperandNum == oper->getOperandNumber() &&
+         "operand overflow");
+
   storage.isUseProjection = true;
 
   if (EnumDecl *enumDecl = userValue->getType().getEnumOrBoundGenericEnum()) {
@@ -1011,6 +1015,10 @@ bool OpaqueStorageAllocation::findProjectionIntoUseImpl(
     assert(!getProjectedDefOperand(userValue)
            && "storage cannot project in two directions.");
 
+    // Avoid handling preposterous types.
+    if (use->getOperandNumber() > UINT16_MAX)
+      continue;
+
     // Recurse through all storage projections to find the uniquely allocated
     // storage. Enum storage cannot be reused across multiple subobjects because
     // it must be initialized via a single init_enum_data_addr instruction.