Merge pull request swiftlang#38670 from MaskRay/noreturn

Replace LLVM_ATTRIBUTE_NORETURN with C++11 [[noreturn]]

Author: compnerd

lib/IRGen/IRGenModule.h

@@ -852,7 +852,7 @@ class IRGenModule {
   llvm::PointerType *getEnumValueWitnessTablePtrTy();
 
   void unimplemented(SourceLoc, StringRef Message);
-  LLVM_ATTRIBUTE_NORETURN
+  [[noreturn]]
   void fatal_unimplemented(SourceLoc, StringRef Message);
   void error(SourceLoc loc, const Twine &message);
 

lib/Serialization/ModuleFile.h

@@ -333,7 +333,7 @@ class ModuleFile
 
   /// Emits one last diagnostic, adds the current module details and errors to
   /// the pretty stack trace, and then aborts.
-  LLVM_ATTRIBUTE_NORETURN void fatal(llvm::Error error) const;
+  [[noreturn]] void fatal(llvm::Error error) const;
   void fatalIfNotSuccess(llvm::Error error) const {
     if (error)
       fatal(std::move(error));
@@ -344,7 +344,7 @@ class ModuleFile
     fatal(expected.takeError());
   }
 
-  LLVM_ATTRIBUTE_NORETURN void fatal() const {
+  [[noreturn]] void fatal() const {
     fatal(llvm::make_error<llvm::StringError>(
         "(see \"While...\" info below)", llvm::inconvertibleErrorCode()));
   }

lib/Serialization/ModuleFileSharedCore.h

@@ -371,7 +371,7 @@ class ModuleFileSharedCore {
 
   /// Emits one last diagnostic, logs the error, and then aborts for the stack
   /// trace.
-  LLVM_ATTRIBUTE_NORETURN void fatal(llvm::Error error) const;
+  [[noreturn]] void fatal(llvm::Error error) const;
   void fatalIfNotSuccess(llvm::Error error) const {
     if (error)
       fatal(std::move(error));