rar: import unrarsrc-5.5.8 for reference

this will allow us to diff against newer version of unrarsrc if we wish to update our port

reference/unrar/coder.cpp

@@ -0,0 +1,48 @@
+
+
+inline unsigned int RangeCoder::GetChar()
+{
+  return(UnpackRead->GetChar());
+}
+
+
+void RangeCoder::InitDecoder(Unpack *UnpackRead)
+{
+  RangeCoder::UnpackRead=UnpackRead;
+
+  low=code=0;
+  range=uint(-1);
+  for (int i=0;i < 4;i++)
+    code=(code << 8) | GetChar();
+}
+
+
+// (int) cast before "low" added only to suppress compiler warnings.
+#define ARI_DEC_NORMALIZE(code,low,range,read)                           \
+{                                                                        \
+  while ((low^(low+range))<TOP || range<BOT && ((range=-(int)low&(BOT-1)),1)) \
+  {                                                                      \
+    code=(code << 8) | read->GetChar();                                  \
+    range <<= 8;                                                         \
+    low <<= 8;                                                           \
+  }                                                                      \
+}
+
+
+inline int RangeCoder::GetCurrentCount() 
+{
+  return (code-low)/(range /= SubRange.scale);
+}
+
+
+inline uint RangeCoder::GetCurrentShiftCount(uint SHIFT) 
+{
+  return (code-low)/(range >>= SHIFT);
+}
+
+
+inline void RangeCoder::Decode()
+{
+  low += range*SubRange.LowCount;
+  range *= SubRange.HighCount-SubRange.LowCount;
+}