Treat link tag as comment (microsoft#25206)

* First attempt at parsing. Doesn't work

But my machine is dying, so this is an emergency commit.

* Parsing sort of works

But it's not right yet; the test I added fails. See the TODO I added.

* Parse link tag as comment

Author: sandersn

src/compiler/parser.ts

@@ -6567,6 +6567,16 @@ namespace ts {
                                     indent += whitespace.length;
                                 }
                                 break;
+                            case SyntaxKind.OpenBraceToken:
+                                state = JSDocState.SavingComments;
+                                if (lookAhead(() => nextJSDocToken() === SyntaxKind.AtToken && tokenIsIdentifierOrKeyword(nextJSDocToken()) && scanner.getTokenText() === "link")) {
+                                    pushComment(scanner.getTokenText());
+                                    nextJSDocToken();
+                                    pushComment(scanner.getTokenText());
+                                    nextJSDocToken();
+                                }
+                                pushComment(scanner.getTokenText());
+                                break;
                             case SyntaxKind.AsteriskToken:
                                 if (state === JSDocState.BeginningOfLine) {
                                     // leading asterisks start recording on the *next* (non-whitespace) token

src/testRunner/unittests/jsDocParsing.ts

@@ -308,6 +308,12 @@ namespace ts {
 * @param {object} o Doc doc
 * @param {string} o.f Doc for f
 */`);
+                parsesCorrectly("",
+`/**
+ * {@link first link}
+ * Inside {@link link text} thing
+ * @see {@link second link text} and {@link Foo|a foo} as well.
+ */`);
             });
         });
         describe("getFirstToken", () => {

tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly..json

@@ -0,0 +1,28 @@
+{
+    "kind": "JSDocComment",
+    "pos": 0,
+    "end": 127,
+    "tags": {
+        "0": {
+            "kind": "JSDocTag",
+            "pos": 63,
+            "end": 68,
+            "atToken": {
+                "kind": "AtToken",
+                "pos": 63,
+                "end": 64
+            },
+            "tagName": {
+                "kind": "Identifier",
+                "pos": 64,
+                "end": 67,
+                "escapedText": "see"
+            },
+            "comment": "{@link second link text} and {@link Foo|a foo} as well."
+        },
+        "length": 1,
+        "pos": 63,
+        "end": 68
+    },
+    "comment": "{@link first link}\nInside {@link link text} thing"
+}