[CAS] swift dependency scanning using CAS for compiler caching (#66366)

Teach swift dependency scanner to use CAS to capture the full dependencies for a build and construct build commands with immutable inputs from CAS.

This allows swift compilation caching using CAS.

include/swift/ClangImporter/ClangImporter.h

@@ -54,6 +54,7 @@ namespace clang {
 namespace tooling {
 namespace dependencies {
   struct ModuleDeps;
+  struct TranslationUnitDeps;
   using ModuleDepsGraph = std::vector<ModuleDeps>;
 }
 }
@@ -431,6 +432,10 @@ public:
       ModuleDependenciesCache &cache,
       const clang::tooling::dependencies::ModuleDepsGraph &clangDependencies);
 
+  void recordBridgingHeaderOptions(
+      ModuleDependencyInfo &MDI,
+      const clang::tooling::dependencies::TranslationUnitDeps &deps);
+
   Optional<const ModuleDependencyInfo*> getModuleDependencies(
       StringRef moduleName, ModuleDependenciesCache &cache,
       InterfaceSubContextDelegate &delegate,