[llvm-pdbutil] Add the ability to dump raw bytes from the file.

Normally we can only make sense of the content of a PDB in terms
of streams and blocks, but in some cases it may be useful to dump
bytes at a specific absolute file offset.  For example, if you
know that some interesting data is at a particular location and
you want to see some surrounding data.

llvm-svn: 306146
diff --git a/llvm/tools/llvm-pdbutil/llvm-pdbutil.h b/llvm/tools/llvm-pdbutil/llvm-pdbutil.h
index 811037a..78cea8f 100644
--- a/llvm/tools/llvm-pdbutil/llvm-pdbutil.h
+++ b/llvm/tools/llvm-pdbutil/llvm-pdbutil.h
@@ -93,11 +93,13 @@
 }
 
 namespace bytes {
-struct BlockRange {
-  uint32_t Min;
-  llvm::Optional<uint32_t> Max;
+struct NumberRange {
+  uint64_t Min;
+  llvm::Optional<uint64_t> Max;
 };
-extern llvm::Optional<BlockRange> DumpBlockRange;
+
+extern llvm::Optional<NumberRange> DumpBlockRange;
+extern llvm::Optional<NumberRange> DumpByteRange;
 extern llvm::cl::list<std::string> DumpStreamData;
 } // namespace bytes