[ScanDependency] Add -experimental-clang-importer-direct-cc1-scan

Add an experimental option to tell dependency scanner to report clang
cc1 args should be used to construct clang importer in all constructed
swift-frontend tasks.

lib/Frontend/ModuleInterfaceLoader.cpp

@@ -1677,6 +1677,8 @@ void InterfaceSubContextDelegateImpl::inheritOptionsForBuildingInterface(
 
   genericSubInvocation.getClangImporterOptions().DirectClangCC1ModuleBuild =
       clangImporterOpts.DirectClangCC1ModuleBuild;
+  genericSubInvocation.getClangImporterOptions().ClangImporterDirectCC1Scan =
+      clangImporterOpts.ClangImporterDirectCC1Scan;
 
   // Validate Clang modules once per-build session flags must be consistent
   // across all module sub-invocations