Do not create Name of the importSpecifier if it isnt identifier, to avoid creating missing symbols

Missing symbols are defined when the declaration doesnt have name,
so if we created node for missing identifier it would end up binding symbol with name (Missing)

src/compiler/parser.ts

@@ -4656,21 +4656,27 @@ module ts {
             // ImportSpecifier:
             //  ImportedBinding
             //  IdentifierName as ImportedBinding
-            var isfirstIdentifierNameNotAnIdentifier = isKeyword(token) && !isIdentifier();
+            var isFirstIdentifierNameNotAnIdentifier = isKeyword(token) && !isIdentifier();
             var start = scanner.getTokenPos();
             var identifierName = parseIdentifierName();
             if (token === SyntaxKind.AsKeyword) {
                 node.propertyName = identifierName;
                 parseExpected(SyntaxKind.AsKeyword);
-                node.name = parseIdentifier();
+                if (isIdentifier()) {
+                    node.name = parseIdentifierName();
+                }
+                else {
+                    parseErrorAtCurrentToken(Diagnostics.Identifier_expected);
+                }
             }
             else {
                 node.name = identifierName;
-                if (isfirstIdentifierNameNotAnIdentifier) {
+                if (isFirstIdentifierNameNotAnIdentifier) {
                     // Report error identifier expected
                     parseErrorAtPosition(start, identifierName.end - start, Diagnostics.Identifier_expected);
                 }
             }
+
             return finishNode(node);
         }