Harden writer of munged bitcode for fuzzing

lib/Bitcode/NaCl/TestUtils/NaClBitcodeMungeUtils.cpp

 //===--- Bitcode/NaCl/TestUtils/NaClBitcodeMungeUtils.cpp - Munge Bitcode -===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // Munge bitcode records utility class NaClMungedBitcode.
@@ skipping 69 matching lines @@
     std::unique_ptr<NaClBitcodeAbbrevRecord>
         Rcd(new NaClBitcodeAbbrevRecord());
     Rcd->read(Records, RecordsSize, RecordTerminator, Index);
     RecordList.push_back(std::move(Rcd));
   }
 }
 
 } // end of namespace llvm
 
 void NaClBitcodeAbbrevRecord::print(raw_ostream &Out) const {
-  NaClBitcodeRecordData::Print(Out << format("%8u", Abbrev) << ": ");
+  NaClBitcodeRecordData::Print(Out << Abbrev << ": ");
 }
 
 void NaClBitcodeAbbrevRecord::read(const uint64_t Vals[], size_t ValsSize,
                                    uint64_t Terminator, size_t &Index) {
   Abbrev = readAsType<unsigned>(Vals, ValsSize, Terminator, Index);
   Code = readAsType<unsigned>(Vals, ValsSize, Terminator, Index);
   Values.clear();
   while (Index < ValsSize) {
     uint64_t Value = Vals[Index++];
     if (Value == Terminator)
@@ skipping 11 matching lines @@
 }
 
 void NaClMungedBitcode::print(raw_ostream &Out) const {
   size_t Indent = 0;
   for (const NaClBitcodeAbbrevRecord &Record : *this) {
     if (Indent && Record.Code == naclbitc::BLK_CODE_EXIT)
       --Indent;
     for (size_t i = 0; i < Indent; ++i) {
       Out << "  ";
     }
+    // Blank fill to make abbreviation indices right align, and then
+    // print record.
+    uint32_t Cutoff = 9999999;
+    while (Record.Abbrev <= Cutoff && Cutoff) {
+      Out << " ";
+      Cutoff /= 10;
+    }
     Out << Record << "\n";
     if (Record.Code == naclbitc::BLK_CODE_ENTER)
       ++Indent;
   }
 }
 
 NaClMungedBitcode::~NaClMungedBitcode() {
   removeEdits();
 }
 
@@ skipping 165 matching lines @@
     case InAfterInsertions:
       if (InsertionsIter != InsertionsIterEnd)
         return;
       Position = InBeforeInsertions;
       ++Index;
       placeAt(MungedBitcode->BeforeInsertionsMap, Index);
       break;
     }
   }
 }