Rebased PNaCl localmods in LLVM to 223109

include/llvm/Support/StreamingMemoryObject.h

Index: include/llvm/Support/StreamingMemoryObject.h
diff --git a/include/llvm/Support/StreamingMemoryObject.h b/include/llvm/Support/StreamingMemoryObject.h
index 66ed521a411c753fdeb0e23f02363de1dd6ca3c2..3bcce66eb92ada33d43eb47097ab2fec66916b9a 100644
--- a/include/llvm/Support/StreamingMemoryObject.h
+++ b/include/llvm/Support/StreamingMemoryObject.h
@@ -23,9 +23,26 @@ namespace llvm {
 /// Interface to data which is actually streamed from a DataStreamer. In
 /// addition to inherited members, it has the dropLeadingBytes and
 /// setKnownObjectSize methods which are not applicable to non-streamed objects.
+/// @LOCALMOD -- Made dropLeadingBytes/setKnownObjectSize virtual.
 class StreamingMemoryObject : public MemoryObject {
+ public:
+  /// Drop s bytes from the front of the stream, pushing the positions of the
+  /// remaining bytes down by s. This is used to skip past the bitcode header,
+  /// since we don't know a priori if it's present, and we can't put bytes
+  /// back into the stream once we've read them.
+  virtual bool dropLeadingBytes(size_t s) = 0;
+
+  /// If the data object size is known in advance, many of the operations can
+  /// be made more efficient, so this method should be called before reading
+  /// starts (although it can be called anytime).
+  virtual void setKnownObjectSize(size_t size) = 0;
+};
+
+/// @LOCALMOD -- split out StreamingMemoryObjectImpl from StreamingMemoryObject.
+/// StreamingMemoryObjectImpl - an implementation of a StreamingMemoryObject.
+class StreamingMemoryObjectImpl : public StreamingMemoryObject {
 public:
-  StreamingMemoryObject(DataStreamer *streamer);
+  StreamingMemoryObjectImpl(DataStreamer *streamer);
   uint64_t getExtent() const override;
   uint64_t readBytes(uint8_t *Buf, uint64_t Size,
                      uint64_t Address) const override;
@@ -43,12 +60,12 @@ public:
   /// remaining bytes down by s. This is used to skip past the bitcode header,
   /// since we don't know a priori if it's present, and we can't put bytes
   /// back into the stream once we've read them.
-  bool dropLeadingBytes(size_t s);
+  bool dropLeadingBytes(size_t s) override;
 
   /// If the data object size is known in advance, many of the operations can
   /// be made more efficient, so this method should be called before reading
   /// starts (although it can be called anytime).
-  void setKnownObjectSize(size_t size);
+  void setKnownObjectSize(size_t size) override;
 
 private:
   const static uint32_t kChunkSize = 4096 * 4;
@@ -81,8 +98,10 @@ private:
     return Pos < BytesRead;
   }
 
-  StreamingMemoryObject(const StreamingMemoryObject&) LLVM_DELETED_FUNCTION;
-  void operator=(const StreamingMemoryObject&) LLVM_DELETED_FUNCTION;
+  StreamingMemoryObjectImpl(
+      const StreamingMemoryObjectImpl&) LLVM_DELETED_FUNCTION;
+  void operator=(
+      const StreamingMemoryObjectImpl&) LLVM_DELETED_FUNCTION;
 };
 
 MemoryObject *getNonStreamedMemoryObject(