[ORC][NFC] Refactor loop to determine name of init symbol in IRMaterializationUnit

[sgraenitz]

Summary

This loop caused me a little headache once, because I didn't see the assigned variable is a member. The refactored version appears more readable to me.

[lhames]

Oh yeah -- that's way better. Thanks!

llvm/lib/ExecutionEngine/Orc/Layer.cpp

for (auto &G : M.global_values()) {
       SymbolFlags[MangledName] = JITSymbolFlags::fromGlobalValue(G);
       SymbolToDefinition[MangledName] = &G;
     }
 
     // If we need an init symbol for this module then create one.
     if (!llvm::empty(getStaticInitGVs(M))) {
       size_t Counter = 0;
 
-      while (true) {
+      do {
         std::string InitSymbolName;
         raw_string_ostream(InitSymbolName)
             << "$." << M.getModuleIdentifier() << ".__inits." << Counter++;
         InitSymbol = ES.intern(InitSymbolName);
-        if (SymbolFlags.count(InitSymbol))
-          continue;
-        SymbolFlags[InitSymbol] =
-            JITSymbolFlags::MaterializationSideEffectsOnly;
-        break;
-      }
+      } while (SymbolFlags.count(InitSymbol));
+
+      SymbolFlags[InitSymbol] = JITSymbolFlags::MaterializationSideEffectsOnly;
     }
   });
 }
 
 IRMaterializationUnit::IRMaterializationUnit(
     ThreadSafeModule TSM, VModuleKey K, SymbolFlagsMap SymbolFlags,
     SymbolStringPtr InitSymbol, SymbolNameToDefinitionMap SymbolToDefinition)
     : MaterializationUnit(std::move(SymbolFlags), std::move(InitSymbol),