Refactor Cider FileState.

The general direction is to make pieces of data that are produced
together to be stored together, and so be available together.

_FileStateLocation is created before FileState, so it is separated.

Any FileState has some unlinked state, so we pass _FileStateUnlinked
into the constructor. In Cider we don't refresh files, we discard
them and recreate. So, '_unlinked' is a final field.

Practically FileState works as a wrapper around _FileStateUnlinked.
It could probably have been inlined into FileState. My excuse for
not doing this is that in DAS, at least at the moment, we keep
FileState instances and refresh them with replacing their unlinked
states. So, they should be separate objects.

Change-Id: I9439a4021e6efa9e4375eceb5eecf534eabda168
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/217860
Reviewed-by: Brian Wilkerson <[email protected]>
Reviewed-by: Keerti Parthasarathy <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/dart/micro/library_analyzer.dart

@@ -110,7 +110,7 @@ class LibraryAnalyzer {
 
     // Parse all files.
     performance.run('parse', (performance) {
-      for (FileState file in _library.libraryFiles) {
+      for (FileState file in _library.files().ofLibrary) {
         if (completionPath == null || file.path == completionPath) {
           units[file] = _parse(
             file: file,
@@ -231,19 +231,19 @@ class LibraryAnalyzer {
 
     if (_analysisOptions.lint) {
       performance.run('computeLints', (performance) {
-        var allUnits = _library.libraryFiles.map((file) {
+        var allUnits = _library.files().ofLibrary.map((file) {
           var content = getFileContent(file);
           return LinterContextUnit(content, units[file]!);
         }).toList();
         for (int i = 0; i < allUnits.length; i++) {
-          _computeLints(_library.libraryFiles[i], allUnits[i], allUnits);
+          _computeLints(_library.files().ofLibrary[i], allUnits[i], allUnits);
         }
       });
     }
 
     // This must happen after all other diagnostics have been computed but
     // before the list of diagnostics has been filtered.
-    for (var file in _library.libraryFiles) {
+    for (var file in _library.files().ofLibrary) {
       IgnoreValidator(
         _getErrorReporter(file),
         _getErrorListener(file).errors,
@@ -472,7 +472,7 @@ class LibraryAnalyzer {
   }
 
   bool _isExistingSource(Source source) {
-    for (var file in _library.directReferencedFiles) {
+    for (var file in _library.files().directReferencedFiles) {
       if (file.uri == source.uri) {
         return file.exists;
       }
@@ -595,7 +595,7 @@ class LibraryAnalyzer {
       } else if (directive is PartDirectiveImpl) {
         StringLiteral partUri = directive.uri;
 
-        FileState partFile = _library.partedFiles[partIndex];
+        FileState partFile = _library.files().parted[partIndex];
         var partUnit = units[partFile]!;
         CompilationUnitElement partElement = _libraryElement.parts[partIndex];
         partUnit.element = partElement;