[llvm] Don't call raw_string_ostream::flush() (NFC)

Don't call raw_string_ostream::flush(), which is essentially a no-op.
As specified in the docs, raw_string_ostream is always unbuffered.
( 65b1361 for further reference )

Author: JOE1994

llvm/lib/Analysis/CallGraphSCCPass.cpp

@@ -453,7 +453,6 @@ bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
         OS << LS;
         CGN->print(OS);
       }
-      OS.flush();
   #endif
       dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, Functions);
     }

llvm/lib/CodeGen/MIRPrinter.cpp

@@ -256,7 +256,6 @@ void MIRPrinter::print(const MachineFunction &MF) {
         .print(MBB);
     IsNewlineNeeded = true;
   }
-  StrOS.flush();
   // Convert machine metadata collected during the print of the machine
   // function.
   convertMachineMetadataNodes(YamlMF, MF, MST);

llvm/lib/DebugInfo/GSYM/DwarfTransformer.cpp

@@ -620,7 +620,6 @@ Error DwarfTransformer::convert(uint32_t NumThreads, OutputAggregator &Out) {
           // Print ThreadLogStorage lines into an actual stream under a lock
           std::lock_guard<std::mutex> guard(LogMutex);
           if (Out.GetOS()) {
-            StrStream.flush();
             Out << storage;
           }
           Out.Merge(ThreadOut);

llvm/lib/IRReader/IRReader.cpp

@@ -124,7 +124,6 @@ LLVMBool LLVMParseIRInContext(LLVMContextRef ContextRef,
       raw_string_ostream os(buf);
 
       Diag.print(nullptr, os, false);
-      os.flush();
 
       *OutMessage = strdup(buf.c_str());
     }

llvm/lib/ObjectYAML/CodeViewYAMLSymbols.cpp

@@ -308,7 +308,6 @@ void UnknownSymbolRecord::map(yaml::IO &io) {
     std::string Str;
     raw_string_ostream OS(Str);
     Binary.writeAsBinary(OS);
-    OS.flush();
     Data.assign(Str.begin(), Str.end());
   }
 }

llvm/lib/TableGen/Record.cpp

@@ -838,7 +838,6 @@ Init *UnOpInit::Fold(Record *CurRec, bool IsFinal) const {
         std::string S;
         raw_string_ostream OS(S);
         OS << *Def->getDef();
-        OS.flush();
         return StringInit::get(RK, S);
       } else {
         // Otherwise, print the value of the variable.

llvm/lib/Target/AMDGPU/AMDGPUMCInstLower.cpp

@@ -321,7 +321,6 @@ void AMDGPUAsmPrinter::emitInstruction(const MachineInstr *MI) {
         HexStream << format("%s%08X", (i > 0 ? " " : ""), CodeDWord);
       }
 
-      DisasmStream.flush();
       DisasmLineMaxLen = std::max(DisasmLineMaxLen, DisasmLine.size());
     }
   }

llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp

@@ -6094,7 +6094,6 @@ bool AMDGPUAsmParser::ParseToEndDirective(const char *AssemblerDirectiveBegin,
                     Twine(AssemblerDirectiveEnd) + Twine(" not found"));
   }
 
-  CollectStream.flush();
   return false;
 }
 

llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp

@@ -904,7 +904,6 @@ std::string AMDGPUTargetID::toString() const {
 
   StreamRep << Processor << Features;
 
-  StreamRep.flush();
   return StringRep;
 }
 

llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp

@@ -596,7 +596,6 @@ std::string NVPTXAsmPrinter::getVirtualRegisterName(unsigned Reg) const {
 
   NameStr << getNVPTXRegClassStr(RC) << MappedVR;
 
-  NameStr.flush();
   return Name;
 }