[ts] raise SyntaxError for declare before getter/setter (#13143)

* fix: raise `SyntaxError` for `declare` before getter/setter

* fix: allow `declare` when class property name is `get` or `set`

packages/babel-parser/src/plugins/typescript/index.js

@@ -67,6 +67,7 @@ const TSErrors = Object.freeze({
   ClassMethodHasReadonly: "Class methods cannot have the 'readonly' modifier",
   ConstructorHasTypeParameters:
     "Type parameters cannot appear on a constructor declaration.",
+  DeclareAccessor: "'declare' is not allowed in %0ters.",
   DeclareClassFieldHasInitializer:
     "Initializers are not allowed in ambient contexts.",
   DeclareFunctionHasImplementation:
@@ -2470,6 +2471,11 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       if (typeParameters && isConstructor) {
         this.raise(typeParameters.start, TSErrors.ConstructorHasTypeParameters);
       }
+
+      // $FlowIgnore
+      if (method.declare && (method.kind === "get" || method.kind === "set")) {
+        this.raise(method.start, TSErrors.DeclareAccessor, method.kind);
+      }
       if (typeParameters) method.typeParameters = typeParameters;
       super.pushClassMethod(
         classBody,