propagate vfs to more places, remove vfs arg

Propagates the VFS to the SemanticInfo that gets used when then
original editor.open is syntactic only.

Removes unnecessary filesystem arg (get filesystem from class field
instead).

Adds test for the VFS being propagated into the SemanticInfo.

Refactors test/SourceKit/CursorInfo/injected_vfs.swift to use
-print-raw-response for all its tests, for consistency.

tools/SourceKit/lib/SwiftLang/SwiftLangSupport.h

@@ -86,13 +86,13 @@ class SwiftEditorDocument :
 public:
 
   SwiftEditorDocument(StringRef FilePath, SwiftLangSupport &LangSupport,
+       llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> fileSystem,
        swift::ide::CodeFormatOptions Options = swift::ide::CodeFormatOptions());
   ~SwiftEditorDocument();
 
   ImmutableTextSnapshotRef
   initializeText(llvm::MemoryBuffer *Buf, ArrayRef<const char *> Args,
-                 bool ProvideSemanticInfo,
-                 llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> FileSystem);
+                 bool ProvideSemanticInfo);
   ImmutableTextSnapshotRef replaceText(unsigned Offset, unsigned Length,
                                        llvm::MemoryBuffer *Buf,
                                        bool ProvideSemanticInfo,