js: Handle exceptions thrown during value printing

If an exception was thrown while printing the last computed value in
the REPL, it would always assert on next input.

Something like this would always assert:

> a=[];Object.defineProperty(a,"0",{get:()=>{throw ""}})
> 1 + 2

1 files changed, 9 insertions, 4 deletions

diff --git a/Userland/Utilities/js.cpp b/Userland/Utilities/js.cpp
index a7538d5107..d7b48407fd 100644
--- a/Userland/Utilities/js.cpp
+++ b/Userland/Utilities/js.cpp
@@ -467,7 +467,7 @@ static bool parse_and_run(JS::Interpreter& interpreter, const StringView& source
         interpreter.run(interpreter.global_object(), *program);
     }
 
-    if (vm->exception()) {
+    auto handle_exception = [&] {
         out("Uncaught exception: ");
         print(vm->exception()->value());
         auto trace = vm->exception()->trace();
@@ -493,10 +493,15 @@ static bool parse_and_run(JS::Interpreter& interpreter, const StringView& source
             }
         }
         vm->clear_exception();
-        return false;
-    }
-    if (s_print_last_result)
+    };
+    if (vm->exception())
+        handle_exception();
+
+    if (s_print_last_result) {
         print(vm->last_value());
+        if (vm->exception())
+            handle_exception();
+    }
     return true;
 }