Remove isExpressionNode assertion

Author: andrewbranch

src/compiler/checker.ts

@@ -6127,7 +6127,6 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             },
             isOptionalParameter,
             isUndefinedIdentifierExpression(node: Identifier) {
-                Debug.assert(isExpressionNode(node));
                 return getSymbolAtLocation(node) === undefinedSymbol;
             },
             isEntityNameVisible(context, entityName, shouldComputeAliasToMakeVisible) {

src/compiler/utilities.ts

@@ -3647,7 +3647,6 @@ export function isInExpressionContext(node: Node): boolean {
         case SyntaxKind.SwitchStatement:
         case SyntaxKind.CaseClause:
         case SyntaxKind.ThrowStatement:
-        case SyntaxKind.ExportAssignment:
             return (parent as ExpressionStatement).expression === node;
         case SyntaxKind.ForStatement:
             const forStatement = parent as ForStatement;