Remove manual byte counting from Opcode::Dump

[teemperor]

Summary

Stream now has byte-counting functionality, so let's use this instead of manual byte
counting.

[davide]

LGTM.

lldb/trunk/source/Core/Opcode.cpp

 #include <memory> // for make_shared
 
 #include <inttypes.h> // for PRIx64
 
 using namespace lldb;
 using namespace lldb_private;
 
 int Opcode::Dump(Stream *s, uint32_t min_byte_width) {
-  int bytes_written = 0;
+  const uint32_t previous_bytes = s->GetWrittenBytes();
   switch (m_type) {
   case Opcode::eTypeInvalid:
-    bytes_written = s->PutCString("<invalid>");
+    s->PutCString("<invalid>");
     break;
   case Opcode::eType8:
-    bytes_written = s->Printf("0x%2.2x", m_data.inst8);
+    s->Printf("0x%2.2x", m_data.inst8);
     break;
   case Opcode::eType16:
-    bytes_written = s->Printf("0x%4.4x", m_data.inst16);
+    s->Printf("0x%4.4x", m_data.inst16);
     break;
   case Opcode::eType16_2:
   case Opcode::eType32:
-    bytes_written = s->Printf("0x%8.8x", m_data.inst32);
+    s->Printf("0x%8.8x", m_data.inst32);
     break;
 
   case Opcode::eType64:
-    bytes_written = s->Printf("0x%16.16" PRIx64, m_data.inst64);
+    s->Printf("0x%16.16" PRIx64, m_data.inst64);
     break;
 
   case Opcode::eTypeBytes:
     for (uint32_t i = 0; i < m_data.inst.length; ++i) {
       if (i > 0)
-        bytes_written += s->PutChar(' ');
-      bytes_written += s->Printf("%2.2x", m_data.inst.bytes[i]);
+        s->PutChar(' ');
+      s->Printf("%2.2x", m_data.inst.bytes[i]);
     }
     break;
   }
 
-  // Add spaces to make sure bytes dispay comes out even in case opcodes aren't
-  // all the same size
-  if (static_cast<uint32_t>(bytes_written) < min_byte_width)
-    bytes_written = s->Printf("%*s", min_byte_width - bytes_written, "");
-  return bytes_written;
+  uint32_t bytes_written_so_far = s->GetWrittenBytes() - previous_bytes;
+  // Add spaces to make sure bytes display comes out even in case opcodes aren't
+  // all the same size.
+  if (bytes_written_so_far < min_byte_width)
+    s->Printf("%*s", min_byte_width - bytes_written_so_far, "");
+  return s->GetWrittenBytes() - previous_bytes;
 }
 
 lldb::ByteOrder Opcode::GetDataByteOrder() const {
   if (m_byte_order != eByteOrderInvalid) {
     return m_byte_order;
   }
   switch (m_type) {
   case Opcode::eTypeInvalid: