Add flag that suppresses exception output using load()

Without this flag, the load() function is very chatty when
an exception is thrown out of it, independent if the
surrounding code catches it or not.

Bug: v8:6972
Change-Id: I4ca82689c42c729716b83e420d9c7f7e2b5213d1
Reviewed-on: https://chromium-review.googlesource.com/781688Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49555}

src/d8.cc

@@ -1425,11 +1425,11 @@ void Shell::Load(const v8::FunctionCallbackInfo<v8::Value>& args) {
       Throw(args.GetIsolate(), "Error loading file");
       return;
     }
-    if (!ExecuteString(
-            args.GetIsolate(), source,
-            String::NewFromUtf8(args.GetIsolate(), *file,
-                                NewStringType::kNormal).ToLocalChecked(),
-            false, true)) {
+    if (!ExecuteString(args.GetIsolate(), source,
+                       String::NewFromUtf8(args.GetIsolate(), *file,
+                                           NewStringType::kNormal)
+                           .ToLocalChecked(),
+                       false, !options.quiet_load)) {
       Throw(args.GetIsolate(), "Error executing file");
       return;
     }
@@ -2896,6 +2896,9 @@ bool Shell::SetOptions(int argc, char* argv[]) {
     } else if (strcmp(argv[i], "--enable-os-system") == 0) {
       options.enable_os_system = true;
       argv[i] = nullptr;
+    } else if (strcmp(argv[i], "--quiet-load") == 0) {
+      options.quiet_load = true;
+      argv[i] = nullptr;
     }
   }
 

src/d8.h

@@ -339,6 +339,7 @@ class ShellOptions {
   bool disable_in_process_stack_traces;
   int read_from_tcp_port;
   bool enable_os_system = false;
+  bool quiet_load = false;
 };
 
 class Shell : public i::AllStatic {