[Transforms] Use default member initialization in CHRStats (NFC)

Author: kazutakahirata

llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp

@@ -145,19 +145,19 @@ FunctionPass *llvm::createControlHeightReductionLegacyPass() {
 namespace {
 
 struct CHRStats {
-  CHRStats() : NumBranches(0), NumBranchesDelta(0),
-               WeightedNumBranchesDelta(0) {}
+  CHRStats() = default;
   void print(raw_ostream &OS) const {
     OS << "CHRStats: NumBranches " << NumBranches
        << " NumBranchesDelta " << NumBranchesDelta
        << " WeightedNumBranchesDelta " << WeightedNumBranchesDelta;
   }
-  uint64_t NumBranches;       // The original number of conditional branches /
-                              // selects
-  uint64_t NumBranchesDelta;  // The decrease of the number of conditional
-                              // branches / selects in the hot paths due to CHR.
-  uint64_t WeightedNumBranchesDelta; // NumBranchesDelta weighted by the profile
-                                     // count at the scope entry.
+  // The original number of conditional branches / selects
+  uint64_t NumBranches = 0;
+  // The decrease of the number of conditional branches / selects in the hot
+  // paths due to CHR.
+  uint64_t NumBranchesDelta = 0;
+  // NumBranchesDelta weighted by the profile count at the scope entry.
+  uint64_t WeightedNumBranchesDelta = 0;
 };
 
 // RegInfo - some properties of a Region.