Harden writer of munged bitcode for fuzzing

lib/Bitcode/NaCl/TestUtils/NaClBitcodeMungeUtils.cpp

Index: lib/Bitcode/NaCl/TestUtils/NaClBitcodeMungeUtils.cpp
diff --git a/lib/Bitcode/NaCl/TestUtils/NaClBitcodeMungeUtils.cpp b/lib/Bitcode/NaCl/TestUtils/NaClBitcodeMungeUtils.cpp
index be28d06fc96c1dea29373fa16ca91a4fab8d30d8..36d532b5787b3bfaea0fbf62b16dfe985183eb21 100644
--- a/lib/Bitcode/NaCl/TestUtils/NaClBitcodeMungeUtils.cpp
+++ b/lib/Bitcode/NaCl/TestUtils/NaClBitcodeMungeUtils.cpp
@@ -87,7 +87,7 @@ void readNaClBitcodeRecordList(NaClBitcodeRecordList &RecordList,
 } // 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,
@@ -119,6 +119,13 @@ void NaClMungedBitcode::print(raw_ostream &Out) const {
     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;