Clean up some inappropriate choices of type in the bitcode reader. None of
these are expected to fix any 64->32 bit real truncation issues.

llvm-svn: 229153
diff --git a/llvm/lib/Bitcode/Reader/BitstreamReader.cpp b/llvm/lib/Bitcode/Reader/BitstreamReader.cpp
index 9d5fab9..ca68257 100644
--- a/llvm/lib/Bitcode/Reader/BitstreamReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitstreamReader.cpp
@@ -253,7 +253,7 @@
 
     BitCodeAbbrevOp::Encoding E = (BitCodeAbbrevOp::Encoding)Read(3);
     if (BitCodeAbbrevOp::hasEncodingData(E)) {
-      unsigned Data = ReadVBR64(5);
+      uint64_t Data = ReadVBR64(5);
 
       // As a special case, handle fixed(0) (i.e., a fixed field with zero bits)
       // and vbr(0) as a literal zero.  This is decoded the same way, and avoids