[llvm] Add triple for SerenityOS

[ADKaster]

Add unit test

[MaskRay]

llvm/include/llvm/TargetParser/Triple.h

681

I know you follow some existing comments, but the code really speaks for itself. I think the commend should be removed.

llvm/unittests/TargetParser/TripleTest.cpp

897 ↗

(On Diff #536935)

Ensure that this is the triple SerenityOS prefers. I.e. you prefer x86_64-pc-serenity instead of x86_64-unknown-serenity

[ADKaster]

remove unecessary comment

llvm/include/llvm/TargetParser/Triple.h

enum OSType {
     Contiki,
     AMDPAL,     // AMD PAL Runtime
     HermitCore, // HermitCore Unikernel/Multikernel
     Hurd,       // GNU/Hurd
     WASI,       // Experimental WebAssembly OS
     Emscripten,
     ShaderModel, // DirectX ShaderModel
     LiteOS,
-    LastOSType = LiteOS
+    Serenity,
+    LastOSType = Serenity
   };
   enum EnvironmentType {
     UnknownEnvironment,
 
     GNU,
     GNUABIN32,
     GNUABI64,
     GNUEABI,
return (getOS() == Triple::Linux || getOS() == Triple::KFreeBSD ||
            !isAndroid();
   }
 
   /// Tests whether the OS is AIX.
   bool isOSAIX() const {
     return getOS() == Triple::AIX;
   }
 
+  /// Tests whether the OS is SerenityOS
+  bool isOSSerenity() const {
+    return getOS() == Triple::Serenity;
+  }
+
   /// Tests whether the OS uses the ELF binary format.
   bool isOSBinFormatELF() const {
     return getObjectFormat() == Triple::ELF;
   }
 
   /// Tests whether the OS uses the COFF binary format.
   bool isOSBinFormatCOFF() const {
     return getObjectFormat() == Triple::COFF;

llvm/lib/TargetParser/Triple.cpp

StringRef Triple::getOSTypeName(OSType Kind) {
   case NVCL: return "nvcl";
   case NaCl: return "nacl";
   case NetBSD: return "netbsd";
   case OpenBSD: return "openbsd";
   case PS4: return "ps4";
   case PS5: return "ps5";
   case RTEMS: return "rtems";
   case Solaris: return "solaris";
+  case Serenity: return "serenity";
   case TvOS: return "tvos";
   case UEFI: return "uefi";
   case WASI: return "wasi";
   case WatchOS: return "watchos";
   case Win32: return "windows";
   case ZOS: return "zos";
   case ShaderModel: return "shadermodel";
   case LiteOS: return "liteos";
return StringSwitch<Triple::OSType>(OSName)
     .StartsWith("contiki", Triple::Contiki)
     .StartsWith("amdpal", Triple::AMDPAL)
     .StartsWith("hermit", Triple::HermitCore)
     .StartsWith("hurd", Triple::Hurd)
     .StartsWith("wasi", Triple::WASI)
     .StartsWith("emscripten", Triple::Emscripten)
     .StartsWith("shadermodel", Triple::ShaderModel)
     .StartsWith("liteos", Triple::LiteOS)
+    .StartsWith("serenity", Triple::Serenity)
     .Default(Triple::UnknownOS);
 }
 
 static Triple::EnvironmentType parseEnvironment(StringRef EnvironmentName) {
   return StringSwitch<Triple::EnvironmentType>(EnvironmentName)
       .StartsWith("eabihf", Triple::EABIHF)
       .StartsWith("eabi", Triple::EABI)
       .StartsWith("gnuabin32", Triple::GNUABIN32)