Bug 1620960 part 1 - Add JSTryNote::isLoop. r=tcampbell

Later patches will use this.

Differential Revision: https://phabricator.services.mozilla.com/D66002

--HG--
extra : moz-landing-system : lando

js/src/vm/JSScript.cpp

@@ -5603,19 +5603,8 @@ void JSScript::updateJitCodeRaw(JSRuntime* rt) {
 
 bool JSScript::hasLoops() {
   for (const JSTryNote& tn : trynotes()) {
-    switch (tn.kind) {
-      case JSTRY_FOR_IN:
-      case JSTRY_FOR_OF:
-      case JSTRY_LOOP:
-        return true;
-      case JSTRY_CATCH:
-      case JSTRY_FINALLY:
-      case JSTRY_FOR_OF_ITERCLOSE:
-      case JSTRY_DESTRUCTURING:
-        break;
-      default:
-        MOZ_ASSERT(false, "Add new try note type to JSScript::hasLoops");
-        break;
+    if (tn.isLoop()) {
+      return true;
     }
   }
   return false;

js/src/vm/JSScript.h

@@ -143,6 +143,21 @@ struct JSTryNote {
 
   template <js::XDRMode mode>
   js::XDRResult XDR(js::XDRState<mode>* xdr);
+
+  bool isLoop() const {
+    switch (kind) {
+      case JSTRY_LOOP:
+      case JSTRY_FOR_IN:
+      case JSTRY_FOR_OF:
+        return true;
+      case JSTRY_CATCH:
+      case JSTRY_FINALLY:
+      case JSTRY_FOR_OF_ITERCLOSE:
+      case JSTRY_DESTRUCTURING:
+        return false;
+    }
+    MOZ_CRASH("Unexpected try note kind");
+  }
 };
 
 namespace js {