[BOLT] Use std::tie to Implment operator< (NFC) (#139404)

Author: kazutakahirata

bolt/include/bolt/Passes/FrameAnalysis.h

@@ -10,6 +10,7 @@
 #define BOLT_PASSES_FRAMEANALYSIS_H
 
 #include "bolt/Passes/StackPointerTracking.h"
+#include <tuple>
 
 namespace llvm {
 namespace bolt {
@@ -53,9 +54,7 @@ struct ArgInStackAccess {
   uint8_t Size;
 
   bool operator<(const ArgInStackAccess &RHS) const {
-    if (StackOffset != RHS.StackOffset)
-      return StackOffset < RHS.StackOffset;
-    return Size < RHS.Size;
+    return std::tie(StackOffset, Size) < std::tie(RHS.StackOffset, RHS.Size);
   }
 };
 

bolt/include/bolt/Passes/PAuthGadgetScanner.h

@@ -43,9 +43,7 @@ struct MCInstInBBReference {
     return BB == RHS.BB && BBIndex == RHS.BBIndex;
   }
   bool operator<(const MCInstInBBReference &RHS) const {
-    if (BB != RHS.BB)
-      return BB < RHS.BB;
-    return BBIndex < RHS.BBIndex;
+    return std::tie(BB, BBIndex) < std::tie(RHS.BB, RHS.BBIndex);
   }
   operator MCInst &() const {
     assert(BB != nullptr);

bolt/include/bolt/Profile/DataReader.h

@@ -90,13 +90,7 @@ struct BranchInfo {
   }
 
   bool operator<(const BranchInfo &RHS) const {
-    if (From < RHS.From)
-      return true;
-
-    if (From == RHS.From)
-      return (To < RHS.To);
-
-    return false;
+    return std::tie(From, To) < std::tie(RHS.From, RHS.To);
   }
 
   /// Merges branch and misprediction counts of \p BI with those of this object.