[clang] 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

Author: JOE1994

clang/include/clang/AST/StmtDataCollectors.td

@@ -55,7 +55,6 @@ class CallExpr {
           // Add a padding character so that 'foo<X, XX>()' != 'foo<XX, X>()'.
           OS << '\n';
         }
-        OS.flush();
 
         addData(ArgString);
       }

clang/lib/AST/DataCollection.cpp

@@ -41,7 +41,6 @@ std::string getMacroStack(SourceLocation Loc, ASTContext &Context) {
     printMacroName(MacroStackStream, Context, Loc);
     Loc = SM.getImmediateMacroCallerLoc(Loc);
   }
-  MacroStackStream.flush();
   return MacroStack;
 }
 

clang/lib/AST/TemplateName.cpp

@@ -439,6 +439,5 @@ const StreamingDiagnostic &clang::operator<<(const StreamingDiagnostic &DB,
   OS << '\'';
   N.print(OS, PrintingPolicy(LO));
   OS << '\'';
-  OS.flush();
   return DB << NameStr;
 }

clang/lib/Basic/Module.cpp

@@ -252,7 +252,6 @@ std::string Module::getFullModuleName(bool AllowStringLiterals) const {
 
   llvm::raw_string_ostream Out(Result);
   printModuleId(Out, Names.rbegin(), Names.rend(), AllowStringLiterals);
-  Out.flush();
 
   return Result;
 }

clang/lib/CodeGen/BackendUtil.cpp

@@ -352,7 +352,6 @@ static std::string flattenClangCommandLine(ArrayRef<std::string> Args,
     llvm::sys::printArg(OS, Arg, /*Quote=*/true);
     PrintedOneArg = true;
   }
-  OS.flush();
   return FlatCmdLine;
 }
 

clang/lib/CodeGen/CodeGenPGO.cpp

@@ -1134,7 +1134,6 @@ void CodeGenPGO::emitCounterRegionMapping(const Decl *D) {
       *CGM.getCoverageMapping(), CGM.getContext().getSourceManager(),
       CGM.getLangOpts(), RegionCounterMap.get(), RegionMCDCState.get());
   MappingGen.emitCounterMapping(D, OS);
-  OS.flush();
 
   if (CoverageMapping.empty())
     return;
@@ -1155,7 +1154,6 @@ CodeGenPGO::emitEmptyCounterMapping(const Decl *D, StringRef Name,
                                 CGM.getContext().getSourceManager(),
                                 CGM.getLangOpts());
   MappingGen.emitEmptyMapping(D, OS);
-  OS.flush();
 
   if (CoverageMapping.empty())
     return;

clang/lib/Driver/Job.cpp

@@ -343,7 +343,6 @@ int Command::Execute(ArrayRef<std::optional<StringRef>> Redirects,
     writeResponseFile(SS);
     buildArgvForResponseFile(Argv);
     Argv.push_back(nullptr);
-    SS.flush();
 
     // Save the response file in the appropriate encoding
     if (std::error_code EC = writeFileWithEncoding(

clang/lib/Driver/ToolChains/HIPUtility.cpp

@@ -446,7 +446,6 @@ void HIP::constructGenerateObjFileFromHIPFatBinary(
   }
   if (HostTriple.isOSLinux() && HostTriple.isOSBinFormatELF())
     ObjStream << "  .section .note.GNU-stack, \"\", @progbits\n";
-  ObjStream.flush();
 
   // Dump the contents of the temp object file gen if the user requested that.
   // We support this option to enable testing of behavior with -###.

clang/lib/Sema/Sema.cpp

@@ -125,7 +125,6 @@ IdentifierInfo *Sema::InventAbbreviatedTemplateParameterTypeName(
   else
     OS << ParamName->getName() << ":auto";
 
-  OS.flush();
   return &Context.Idents.get(OS.str());
 }
 

clang/lib/Sema/SemaChecking.cpp

@@ -6559,7 +6559,6 @@ CheckFormatHandler::HandleInvalidConversionSpecifier(unsigned argIndex,
       OS << "\\u" << llvm::format("%04x", CodePoint);
     else
       OS << "\\U" << llvm::format("%08x", CodePoint);
-    OS.flush();
     Specifier = CodePointStr;
   }