[ORC] Don't require a null-terminator on MemoryBuffers for objects in archives.

The MemoryBuffer::getMemBuffer method's RequiresNullTerminator parameter
defaults to true, but object files are not null terminated so we need to
explicitly pass false here.
diff --git a/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp b/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp
index a98445a..50f1ca3 100644
--- a/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp
@@ -349,8 +349,8 @@
     MemoryBufferRef ChildBufferRef(ChildBufferInfo.first,
                                    ChildBufferInfo.second);
 
-    if (auto Err =
-            L.add(JD, MemoryBuffer::getMemBuffer(ChildBufferRef), VModuleKey()))
+    if (auto Err = L.add(JD, MemoryBuffer::getMemBuffer(ChildBufferRef, false),
+                         VModuleKey()))
       return Err;
   }