Add 'bigint' to type keywords (#28537)

Author: Andy

src/harness/fourslash.ts

@@ -4447,7 +4447,7 @@ namespace FourSlashInterface {
         export const keywords: ReadonlyArray<ExpectedCompletionEntryObject> = keywordsWithUndefined.filter(k => k.name !== "undefined");
 
         export const typeKeywords: ReadonlyArray<ExpectedCompletionEntryObject> =
-            ["false", "null", "true", "void", "any", "boolean", "keyof", "never", "number", "object", "string", "symbol", "undefined", "unique", "unknown"].map(keywordEntry);
+            ["false", "null", "true", "void", "any", "boolean", "keyof", "never", "number", "object", "string", "symbol", "undefined", "unique", "unknown", "bigint"].map(keywordEntry);
 
         const globalTypeDecls: ReadonlyArray<ExpectedCompletionEntryObject> = [
             interfaceEntry("Symbol"),

src/services/utilities.ts

@@ -1212,6 +1212,7 @@ namespace ts {
 
     export const typeKeywords: ReadonlyArray<SyntaxKind> = [
         SyntaxKind.AnyKeyword,
+        SyntaxKind.BigIntKeyword,
         SyntaxKind.BooleanKeyword,
         SyntaxKind.FalseKeyword,
         SyntaxKind.KeyOfKeyword,

tests/cases/fourslash/completionsTypeKeywords.ts

@@ -6,5 +6,5 @@
 
 verify.completions({
     marker: "",
-    exact: ["T", "false", "null", "true", "void", "any", "boolean", "keyof", "never", "number", "object", "string", "symbol", "undefined", "unique", "unknown"],
+    exact: ["T", ...completion.typeKeywords],
 });