BinaryStream - fix static analyzer warnings. NFCI.

- uninitialized variables
 - documention warnings
 - shadow variable names

include/llvm/Support/BinaryStreamArray.h

@@ -133,9 +133,9 @@ public:
   Extractor &getExtractor() { return E; }
 
   BinaryStreamRef getUnderlyingStream() const { return Stream; }
-  void setUnderlyingStream(BinaryStreamRef S, uint32_t Skew = 0) {
-    Stream = S;
-    this->Skew = Skew;
+  void setUnderlyingStream(BinaryStreamRef NewStream, uint32_t NewSkew = 0) {
+    Stream = NewStream;
+    Skew = NewSkew;
   }
 
   void drop_front() { Skew += begin()->length(); }
@@ -143,7 +143,7 @@ public:
 private:
   BinaryStreamRef Stream;
   Extractor E;
-  uint32_t Skew;
+  uint32_t Skew = 0;
 };
 
 template <typename ValueType, typename Extractor>

include/llvm/Support/BinaryStreamReader.h

@@ -148,14 +148,14 @@ public:
   /// returns an appropriate error code.
   Error readStreamRef(BinaryStreamRef &Ref, uint32_t Length);
 
-  /// Read \p Length bytes from the underlying stream into \p Stream.  This is
+  /// Read \p Length bytes from the underlying stream into \p Ref.  This is
   /// equivalent to calling getUnderlyingStream().slice(Offset, Length).
   /// Updates the stream's offset to point after the newly read object.  Never
   /// causes a copy.
   ///
   /// \returns a success error code if the data was successfully read, otherwise
   /// returns an appropriate error code.
-  Error readSubstream(BinarySubstreamRef &Stream, uint32_t Size);
+  Error readSubstream(BinarySubstreamRef &Ref, uint32_t Length);
 
   /// Get a pointer to an object of type T from the underlying stream, as if by
   /// memcpy, and store the result into \p Dest.  It is up to the caller to

include/llvm/Support/BinaryStreamRef.h

@@ -198,7 +198,7 @@ public:
 };
 
 struct BinarySubstreamRef {
-  uint32_t Offset;            // Offset in the parent stream
+  uint32_t Offset = 0;        // Offset in the parent stream
   BinaryStreamRef StreamData; // Stream Data
 
   BinarySubstreamRef slice(uint32_t Off, uint32_t Size) const {
@@ -211,8 +211,8 @@ struct BinarySubstreamRef {
   BinarySubstreamRef keep_front(uint32_t N) const { return slice(0, N); }
 
   std::pair<BinarySubstreamRef, BinarySubstreamRef>
-  split(uint32_t Offset) const {
-    return std::make_pair(keep_front(Offset), drop_front(Offset));
+  split(uint32_t Off) const {
+    return std::make_pair(keep_front(Off), drop_front(Off));
   }
 
   uint32_t size() const { return StreamData.getLength(); }

lib/Support/BinaryStreamReader.cpp

@@ -139,10 +139,10 @@ Error BinaryStreamReader::readStreamRef(BinaryStreamRef &Ref, uint32_t Length) {
   return Error::success();
 }
 
-Error BinaryStreamReader::readSubstream(BinarySubstreamRef &Stream,
-                                        uint32_t Size) {
-  Stream.Offset = getOffset();
-  return readStreamRef(Stream.StreamData, Size);
+Error BinaryStreamReader::readSubstream(BinarySubstreamRef &Ref,
+                                        uint32_t Length) {
+  Ref.Offset = getOffset();
+  return readStreamRef(Ref.StreamData, Length);
 }
 
 Error BinaryStreamReader::skip(uint32_t Amount) {