[llvm] [BOLT][NFC] Simplify getOrCreate/analyze/populate/emitJumpTable (PR #132108)

[Maksim Panchenko via llvm-commits]

================
@@ -809,52 +809,50 @@ void BinaryEmitter::emitJumpTable(const JumpTable &JT, MCSection *HotSection,
     Streamer.switchSection(JT.Count > 0 ? HotSection : ColdSection);
     Streamer.emitValueToAlignment(Align(JT.EntrySize));
   }
-  MCSymbol *LastLabel = nullptr;
+  MCSymbol *JTLabel = nullptr;
   uint64_t Offset = 0;
   for (MCSymbol *Entry : JT.Entries) {
     auto LI = JT.Labels.find(Offset);
-    if (LI != JT.Labels.end()) {
-      LLVM_DEBUG({
-        dbgs() << "BOLT-DEBUG: emitting jump table " << LI->second->getName()
-               << " (originally was at address 0x"
-               << Twine::utohexstr(JT.getAddress() + Offset)
-               << (Offset ? ") as part of larger jump table\n" : ")\n");
-      });
-      if (!LabelCounts.empty()) {
-        LLVM_DEBUG(dbgs() << "BOLT-DEBUG: jump table count: "
-                          << LabelCounts[LI->second] << '\n');
-        if (LabelCounts[LI->second] > 0)
-          Streamer.switchSection(HotSection);
-        else
-          Streamer.switchSection(ColdSection);
-        Streamer.emitValueToAlignment(Align(JT.EntrySize));
-      }
-      // Emit all labels registered at the address of this jump table
-      // to sync with our global symbol table.  We may have two labels
-      // registered at this address if one label was created via
-      // getOrCreateGlobalSymbol() (e.g. LEA instructions referencing
-      // this location) and another via getOrCreateJumpTable().  This
-      // creates a race where the symbols created by these two
-      // functions may or may not be the same, but they are both
-      // registered in our symbol table at the same address. By
-      // emitting them all here we make sure there is no ambiguity
-      // that depends on the order that these symbols were created, so
-      // whenever this address is referenced in the binary, it is
-      // certain to point to the jump table identified at this
-      // address.
-      if (BinaryData *BD = BC.getBinaryDataByName(LI->second->getName())) {
-        for (MCSymbol *S : BD->getSymbols())
-          Streamer.emitLabel(S);
-      } else {
-        Streamer.emitLabel(LI->second);
-      }
-      LastLabel = LI->second;
+    if (LI == JT.Labels.end())
+      goto emitEntry;
+    JTLabel = LI->second;
+    LLVM_DEBUG({
+      dbgs() << "BOLT-DEBUG: emitting jump table " << JTLabel->getName()
+             << " (originally was at address 0x"
+             << Twine::utohexstr(JT.getAddress() + Offset)
+             << (Offset ? ") as part of larger jump table\n" : ")\n");
+    });
+    if (!LabelCounts.empty()) {
+      uint64_t JTCount = LabelCounts[JTLabel];
----------------
maksfb wrote:

nit:
```suggestion
      const uint64_t JTCount = LabelCounts[JTLabel];
```

https://github.com/llvm/llvm-project/pull/132108