Remove BitcodeReader::setBufferOwned.

We do have use cases for the bitcode reader owning the buffer or not, but we
always know which one we have when we construct it.

It might be possible to simplify this further, but this is a step in the
right direction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211205 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Bitcode/ReaderWriter.h

@@ -30,7 +30,8 @@ namespace llvm {
   /// deserialization of function bodies.  If successful, this takes ownership
   /// of 'buffer. On error, this *does not* take ownership of Buffer.
   ErrorOr<Module *> getLazyBitcodeModule(MemoryBuffer *Buffer,
-                                         LLVMContext &Context);
+                                         LLVMContext &Context,
+                                         bool BufferOwned = true);
 
   /// getStreamedBitcodeModule - Read the header of the specified stream
   /// and prepare for lazy deserialization and streaming of function bodies.