fix: consider case like a${1}

Author: CaiCongcong

src/parser.ts

@@ -4296,11 +4296,22 @@ export class Parser extends DiagnosticEmitter {
           tn.readIdentifier();
           break;
         }
-        case Token.STRINGLITERAL:
-        case Token.TEMPLATELITERAL: {
+        case Token.STRINGLITERAL:{
           tn.readString();
           break;
         }
+        case Token.TEMPLATELITERAL: {
+          if (tn.readingTemplateString) {
+            tn.readString(CharCode.BACKTICK);
+          } else {
+            tn.readString();
+          }
+          // in readString, tn.pos consume '${'
+          if (tn.readingTemplateString) {
+            ++depth;
+          }
+          break;
+        }
         case Token.INTEGERLITERAL: {
           tn.readInteger();
           tn.checkForIdentifierStartAfterNumericLiteral();