[disassembler] Print code offsets as hex

Another little oversight from https://crrev.com/c/2978252: Code offsets
should be printed in hexadecimal representation, not decimal.

R=delphick@chromium.org

Change-Id: I9e30a1d5d40451e9eb2fc905756d51458acbf819
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3000964
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75519}

src/diagnostics/disassembler.cc

@@ -364,7 +364,7 @@ static int DecodeIt(Isolate* isolate, ExternalReferenceEncoder* ref_encoder,
       // If this is the given "current" pc, make it yellow and bold.
       out << "\033[33;1m";
     }
-    out << static_cast<void*>(prev_pc) << "  " << std::setw(4)
+    out << static_cast<void*>(prev_pc) << "  " << std::setw(4) << std::hex
         << prev_pc - begin << "  ";
 
     // Instruction.