PredictableMemOpt: Fix source location for injected destroys

It's not correct to copy the location from an instruction and turn it into a
RegularLocation if the Location was, e.g., a CleanupLocation. It's always safe
to use a compilergenerated location instead.

Caught by the dihole verification int the source compatibility suite.

rdar://107984038

Author: adrian-prantl

lib/SILOptimizer/Mandatory/PredictableMemOpt.cpp

@@ -1219,7 +1219,8 @@ void AvailableValueAggregator::addHandOffCopyDestroysForPhis(
     // Otherwise, we need to insert one last destroy after the load for our phi.
     auto next = std::next(load->getIterator());
     SILBuilderWithScope builder(next);
-    builder.emitDestroyValueOperation(RegularLocation(next->getLoc()), phi);
+    builder.emitDestroyValueOperation(
+        RegularLocation::getAutoGeneratedLocation(), phi);
   }
 
   // Alright! In summary, we just lifetime extended all of our phis,
@@ -1251,7 +1252,8 @@ void AvailableValueAggregator::addMissingDestroysForCopiedValues(
         assert(li->getParent() == load->getParent());
         auto next = std::next(load->getIterator());
         SILBuilderWithScope builder(next);
-        builder.emitDestroyValueOperation(RegularLocation(next->getLoc()), li);
+        builder.emitDestroyValueOperation(
+            RegularLocation::getAutoGeneratedLocation(), li);
         continue;
       }
     }
@@ -1301,7 +1303,8 @@ void AvailableValueAggregator::addMissingDestroysForCopiedValues(
     // Otherwise, we need to insert one last destroy after the load for our phi.
     auto next = std::next(load->getIterator());
     SILBuilderWithScope builder(next);
-    builder.emitDestroyValueOperation(RegularLocation(next->getLoc()), cvi);
+    builder.emitDestroyValueOperation(
+        RegularLocation::getAutoGeneratedLocation(), cvi);
   }
 }