Separate the C++ and Objective-C generated header output types.

Otherwise, when an output file map is provided, we'll use the same
path for both. Fixes rdar://87987062.

Author: DougGregor

include/swift/Basic/FileTypes.def

@@ -60,6 +60,7 @@ TYPE("llvm-ir",             LLVM_IR,                   "ll",              "")
 TYPE("llvm-bc",             LLVM_BC,                   "bc",              "")
 TYPE("diagnostics",         SerializedDiagnostics,     "dia",             "")
 TYPE("objc-header",         ObjCHeader,                "h",               "")
+TYPE("cxx-header",          CXXHeader,                 "h",               "")
 TYPE("swift-dependencies",  SwiftDeps,                 "swiftdeps",       "")
 TYPE("external-swift-dependencies", ExternalSwiftDeps,  "swiftdeps.external",  "")
 TYPE("remap",               Remapping,                 "remap",           "")

lib/Basic/FileTypes.cpp

@@ -74,6 +74,7 @@ bool file_types::isTextual(ID Id) {
   case file_types::TY_RawSIL:
   case file_types::TY_LLVM_IR:
   case file_types::TY_ObjCHeader:
+  case file_types::TY_CXXHeader:
   case file_types::TY_AutolinkFile:
   case file_types::TY_ImportedModules:
   case file_types::TY_TBD:
@@ -132,6 +133,7 @@ bool file_types::isAfterLLVM(ID Id) {
   case file_types::TY_ASTDump:
   case file_types::TY_RawSIL:
   case file_types::TY_ObjCHeader:
+  case file_types::TY_CXXHeader:
   case file_types::TY_AutolinkFile:
   case file_types::TY_Image:
   case file_types::TY_dSYM:
@@ -182,6 +184,7 @@ bool file_types::isPartOfSwiftCompilation(ID Id) {
   case file_types::TY_Object:
   case file_types::TY_Dependencies:
   case file_types::TY_ObjCHeader:
+  case file_types::TY_CXXHeader:
   case file_types::TY_AutolinkFile:
   case file_types::TY_PCH:
   case file_types::TY_ImportedModules:

lib/Driver/Driver.cpp

@@ -1980,7 +1980,8 @@ void Driver::buildActions(SmallVectorImpl<const Action *> &TopLevelActions,
       if (Arg *A = Args.getLastArg(options::OPT_import_objc_header)) {
         StringRef Value = A->getValue();
         auto Ty = TC.lookupTypeForExtension(llvm::sys::path::extension(Value));
-        if (Ty == file_types::TY_ObjCHeader) {
+        if (Ty == file_types::TY_ObjCHeader ||
+            Ty == file_types::TY_CXXHeader) {
           auto *HeaderInput = C.createAction<InputAction>(*A, Ty);
           StringRef PersistentPCHDir;
           if (const Arg *A = Args.getLastArg(options::OPT_pch_output_dir)) {
@@ -2064,6 +2065,7 @@ void Driver::buildActions(SmallVectorImpl<const Action *> &TopLevelActions,
       case file_types::TY_LLVM_BC:
       case file_types::TY_SerializedDiagnostics:
       case file_types::TY_ObjCHeader:
+      case file_types::TY_CXXHeader:
       case file_types::TY_ClangModuleFile:
       case file_types::TY_SwiftDeps:
       case file_types::TY_ExternalSwiftDeps:

lib/Driver/ToolChains.cpp

@@ -667,6 +667,7 @@ const char *ToolChain::JobContext::computeFrontendModeForCompile() const {
   case file_types::TY_SwiftModuleDocFile:
   case file_types::TY_SerializedDiagnostics:
   case file_types::TY_ObjCHeader:
+  case file_types::TY_CXXHeader:
   case file_types::TY_Image:
   case file_types::TY_SwiftDeps:
   case file_types::TY_ExternalSwiftDeps:
@@ -927,6 +928,7 @@ ToolChain::constructInvocation(const BackendJobAction &job,
     case file_types::TY_SwiftModuleDocFile:
     case file_types::TY_SerializedDiagnostics:
     case file_types::TY_ObjCHeader:
+    case file_types::TY_CXXHeader:
     case file_types::TY_Image:
     case file_types::TY_SwiftDeps:
     case file_types::TY_ExternalSwiftDeps:

lib/Frontend/ArgsToFrontendOutputsConverter.cpp

@@ -444,7 +444,7 @@ SupplementaryOutputPathsComputer::computeOutputPathsForOneInput(
 
   auto cxxHeaderOutputPath = determineSupplementaryOutputFilename(
       OPT_emit_cxx_header, pathsFromArguments.CxxHeaderOutputPath,
-      file_types::TY_ObjCHeader, "",
+      file_types::TY_CXXHeader, "",
       defaultSupplementaryOutputPathExcludingExtension);
 
   auto loadedModuleTracePath = determineSupplementaryOutputFilename(
@@ -587,7 +587,7 @@ createFromTypeToPathMap(const TypeToPathMap *map) {
     return paths;
   const std::pair<file_types::ID, std::string &> typesAndStrings[] = {
       {file_types::TY_ObjCHeader, paths.ObjCHeaderOutputPath},
-      {file_types::TY_ObjCHeader, paths.CxxHeaderOutputPath},
+      {file_types::TY_CXXHeader, paths.CxxHeaderOutputPath},
       {file_types::TY_SwiftModuleFile, paths.ModuleOutputPath},
       {file_types::TY_SwiftModuleDocFile, paths.ModuleDocOutputPath},
       {file_types::TY_SwiftSourceInfoFile, paths.ModuleSourceInfoOutputPath},