[clang][deps] NFC: Remove unused FullDependencies member

[jansvoboda11]

Summary

This patch removes the FullDependencies::AdditionalNonPathCommandLine member, as it's value-initialized and never mutated.

[dexonsmith]

LGTM.

clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h

struct FullDependencies {
 
   /// A list of modules this translation unit directly depends on, not including
   /// transitive dependencies.
   ///
   /// This may include modules with a different context hash when it can be
   /// determined that the differences are benign for this compilation.
   std::vector<ModuleID> ClangModuleDeps;
 
-  /// A partial addtional set of command line arguments that can be used to
-  /// build this translation unit.
-  ///
-  /// Call \c getFullAdditionalCommandLine() to get a command line suitable for
-  /// appending to the original command line to pass to clang.
-  std::vector<std::string> AdditionalNonPathCommandLine;
-
   /// Gets the full addtional command line suitable for appending to the
   /// original command line to pass to clang.
   ///
   /// \param LookupPCMPath this function is called to fill in `-fmodule-file=`
   ///                      flags and for the `-o` flag. It needs to return a
   ///                      path for where the PCM for the given module is to
   ///                      be located.
   /// \param LookupModuleDeps this fucntion is called to collect the full

clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp

 
 namespace clang{
 namespace tooling{
 namespace dependencies{
 
 std::vector<std::string> FullDependencies::getAdditionalCommandLine(
     std::function<StringRef(ModuleID)> LookupPCMPath,
     std::function<const ModuleDeps &(ModuleID)> LookupModuleDeps) const {
-  std::vector<std::string> Ret = AdditionalNonPathCommandLine;
-
-  Ret.push_back("-fno-implicit-modules");
-  Ret.push_back("-fno-implicit-module-maps");
+  std::vector<std::string> Ret{
+      "-fno-implicit-modules",
+      "-fno-implicit-module-maps",
+  };
 
   std::vector<std::string> PCMPaths;
   std::vector<std::string> ModMapPaths;
   dependencies::detail::collectPCMAndModuleMapPaths(
       ClangModuleDeps, LookupPCMPath, LookupModuleDeps, PCMPaths, ModMapPaths);
   for (const std::string &PCMPath : PCMPaths)
     Ret.push_back("-fmodule-file=" + PCMPath);
   for (const std::string &ModMapPath : ModMapPaths)