[llvm] [TableGen] Use llvm::interleaved (NFC) (PR #137483)

[Kazu Hirata via llvm-commits]

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@@ -395,22 +396,16 @@ void CallingConvEmitter::emitArgRegisterLists(raw_ostream &O) {
 
   O << "\n#else\n\n";
 
-  for (auto &Entry : AssignedRegsMap) {
-    const std::string &RegName = Entry.first;
-    std::set<std::string> &Registers = Entry.second;
-
+  for (const auto &[RegName, Registers] : AssignedRegsMap) {
     if (RegName.empty())
       continue;
 
-    O << "const MCRegister " << Entry.first << "_ArgRegs[] = { ";
+    O << "const MCRegister " << RegName << "_ArgRegs[] = { ";
 
-    if (Registers.empty()) {
+    if (Registers.empty())
       O << "0";
-    } else {
-      ListSeparator LS;
-      for (const std::string &Reg : Registers)
-        O << LS << Reg;
-    }
+    else
+      O << llvm::interleaved(Registers);
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kazutakahirata wrote:

Hmm.  We should be OK here.  `LS` evaluates to an empty string for the first reference.  It evaluates to `", "` for subsequent references.

https://github.com/llvm/llvm-project/pull/137483