Keep track of why files are in the program (microsoft#40011)

* --explainFiles currently hardcoded

* Move configFileSpecs to configFile so it can be used in program later

* Explain root file inclusion reason and explain include files in the log

* Baseline explainFiles

* Fix incorrectly reporting of file list two times in --b mode

* Fix unnecessary new lines in output represented incorretly in the baseline

* More tests

* More cleaning up

* Keep listing files in same order as list files, just add explaination

* Fix double listing of file names when the program has errors

* Make diagnostic chains for file include reason

* Add explaination for the file include to diagnostics for program

* Harness ls incorrectly adding tsconfig as the root file

* Fix incorrect use of path for calculating absolute path

* Fix the root file in fourslash

* Test project service options merge

* Add config file name to matched by include explaination

* Add test for when the file changes and program is reused completely but related file information is reattached to correct location

* Handle file preprocessing diagnostics updates when program is reused and related information location changes

* Moved types to types.ts

* Refactoring and cleanup

* More cleanup

* More refatoring

* Handle synthetic imports

* Baselines after merge

Author: sheetalkamat

src/compiler/commandLineParser.ts

@@ -1196,6 +1196,158 @@
         "category": "Error",
         "code": 1392
     },
+    "Imported via {0} from file '{1}'": {
+        "category": "Message",
+        "code": 1393
+    },
+    "Imported via {0} from file '{1}' with packageId '{2}'": {
+        "category": "Message",
+        "code": 1394
+    },
+    "Imported via {0} from file '{1}' to import 'importHelpers' as specified in compilerOptions": {
+        "category": "Message",
+        "code": 1395
+    },
+    "Imported via {0} from file '{1}' with packageId '{2}' to import 'importHelpers' as specified in compilerOptions": {
+        "category": "Message",
+        "code": 1396
+    },
+    "Imported via {0} from file '{1}' to import 'jsx' and 'jsxs' factory functions": {
+        "category": "Message",
+        "code": 1397
+    },
+    "Imported via {0} from file '{1}' with packageId '{2}' to import 'jsx' and 'jsxs' factory functions": {
+        "category": "Message",
+        "code": 1398
+    },
+    "File is included via import here.": {
+        "category": "Message",
+        "code": 1399
+    },
+    "Referenced via '{0}' from file '{1}'": {
+        "category": "Message",
+        "code": 1400
+    },
+    "File is included via reference here.": {
+        "category": "Message",
+        "code": 1401
+    },
+    "Type library referenced via '{0}' from file '{1}'": {
+        "category": "Message",
+        "code": 1402
+    },
+    "Type library referenced via '{0}' from file '{1}' with packageId '{2}'": {
+        "category": "Message",
+        "code": 1403
+    },
+    "File is included via type library reference here.": {
+        "category": "Message",
+        "code": 1404
+    },
+    "Library referenced via '{0}' from file '{1}'": {
+        "category": "Message",
+        "code": 1405
+    },
+    "File is included via library reference here.": {
+        "category": "Message",
+        "code": 1406
+    },
+    "Matched by include pattern '{0}' in '{1}'": {
+        "category": "Message",
+        "code": 1407
+    },
+    "File is matched by include pattern specified here.": {
+        "category": "Message",
+        "code": 1408
+    },
+    "Part of 'files' list in tsconfig.json": {
+        "category": "Message",
+        "code": 1409
+    },
+    "File is matched by 'files' list specified here.": {
+        "category": "Message",
+        "code": 1410
+    },
+    "Output from referenced project '{0}' included because '{1}' specified": {
+        "category": "Message",
+        "code": 1411
+    },
+    "Output from referenced project '{0}' included because '--module' is specified as 'none'": {
+        "category": "Message",
+        "code": 1412
+    },
+    "File is output from referenced project specified here.": {
+        "category": "Message",
+        "code": 1413
+    },
+    "Source from referenced project '{0}' included because '{1}' specified": {
+        "category": "Message",
+        "code": 1414
+    },
+    "Source from referenced project '{0}' included because '--module' is specified as 'none'": {
+        "category": "Message",
+        "code": 1415
+    },
+    "File is source from referenced project specified here.": {
+        "category": "Message",
+        "code": 1416
+    },
+    "Entry point of type library '{0}' specified in compilerOptions": {
+        "category": "Message",
+        "code": 1417
+    },
+    "Entry point of type library '{0}' specified in compilerOptions with packageId '{1}'": {
+        "category": "Message",
+        "code": 1418
+    },
+    "File is entry point of type library specified here.": {
+        "category": "Message",
+        "code": 1419
+    },
+    "Entry point for implicit type library '{0}'": {
+        "category": "Message",
+        "code": 1420
+    },
+    "Entry point for implicit type library '{0}' with packageId '{1}'": {
+        "category": "Message",
+        "code": 1421
+    },
+    "Library '{0}' specified in compilerOptions": {
+        "category": "Message",
+        "code": 1422
+    },
+    "File is library specified here.": {
+        "category": "Message",
+        "code": 1423
+    },
+    "Default library": {
+        "category": "Message",
+        "code": 1424
+    },
+    "Default library for target '{0}'": {
+        "category": "Message",
+        "code": 1425
+    },
+    "File is default library for target specified here.": {
+        "category": "Message",
+        "code": 1426
+    },
+    "Root file specified for compilation": {
+        "category": "Message",
+        "code": 1427
+    },
+    "File is output of project reference source '{0}'": {
+        "category": "Message",
+        "code": 1428
+    },
+    "File redirects to file '{0}'": {
+        "category": "Message",
+        "code": 1429
+    },
+    "The file is in the program because:": {
+        "category": "Message",
+        "code": 1430
+    },
     "The types of '{0}' are incompatible between these types.": {
         "category": "Error",
         "code": 2200
@@ -4748,6 +4900,10 @@
         "category": "Error",
         "code": 6504
     },
+    "Print names of files and the reason they are part of the compilation.": {
+        "category": "Message",
+        "code": 6505
+    },
     "Require undeclared properties from index signatures to use element accesses.": {
         "category": "Error",
         "code": 6803