Use some string predicates that perform their own keyword lookup.

Author: DanielRosenwasser

src/compiler/binder.ts

@@ -2420,7 +2420,6 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
             !(node.flags & NodeFlags.JSDoc) &&
             !isIdentifierName(node)) {
 
-
             const originalKeywordKind = stringToToken(node.escapedText as string);
             if (originalKeywordKind === undefined) {
                 return;

src/services/codefixes/convertToEsModule.ts

@@ -50,10 +50,10 @@ import {
     isExportsOrModuleExportsOrAlias,
     isFunctionExpression,
     isIdentifier,
-    isNonContextualKeyword,
     isObjectLiteralExpression,
     isPropertyAccessExpression,
     isRequireCall,
+    isStringANonContextualKeyword,
     isVariableStatement,
     makeImport,
     map,
@@ -75,7 +75,6 @@ import {
     SourceFile,
     Statement,
     StringLiteralLike,
-    stringToToken,
     SymbolFlags,
     SyntaxKind,
     textChanges,
@@ -163,9 +162,7 @@ function collectExportRenames(sourceFile: SourceFile, checker: TypeChecker, iden
     const res = new Map<string, string>();
     forEachExportReference(sourceFile, node => {
         const text = node.name.text;
-        const keywordKind = stringToToken(text);
-        if (!res.has(text) && (keywordKind !== undefined && isNonContextualKeyword(keywordKind)
-            || checker.resolveName(text, node, SymbolFlags.Value, /*excludeGlobals*/ true))) {
+        if (!res.has(text) && (isStringANonContextualKeyword(text) || checker.resolveName(text, node, SymbolFlags.Value, /*excludeGlobals*/ true))) {
             // Unconditionally add an underscore in case `text` is a keyword.
             res.set(text, makeUniqueName(`_${text}`, identifiers));
         }

src/services/completions.ts

@@ -217,6 +217,7 @@ import {
     isStatement,
     isStatic,
     isString,
+    isStringAKeyword,
     isStringANonContextualKeyword,
     isStringLiteralLike,
     isStringLiteralOrTemplate,
@@ -4827,8 +4828,7 @@ function tryGetObjectTypeDeclarationCompletionContainer(sourceFile: SourceFile,
             }
             break;
        case SyntaxKind.Identifier: {
-            const originalKeywordKind = stringToToken((location as Identifier).text);
-            if (originalKeywordKind && isKeyword(originalKeywordKind)) {
+            if (isStringAKeyword((location as Identifier).text)) {
                 return undefined;
             }
             // class c { public prop = c| }