core: remove some unnecessary heap allocations

core/runtime.rs

@@ -155,19 +155,18 @@ fn v8_init(v8_platform: Option<v8::UniquePtr<v8::Platform>>) {
  v8::V8::initialize_platform(v8_platform);
  v8::V8::initialize();
 
- let argv = vec![
- "".to_string(),
- "--wasm-test-streaming".to_string(),
+ let flags = concat!(
+ "--wasm-test-streaming",
  // TODO(ry) This makes WASM compile synchronously. Eventually we should
  // remove this to make it work asynchronously too. But that requires getting
  // PumpMessageLoop and RunMicrotasks setup correctly.
  // See https://github.com/denoland/deno/issues/2544
- "--no-wasm-async-compilation".to_string(),
- "--harmony-top-level-await".to_string(),
- "--harmony-import-assertions".to_string(),
- "--no-validate-asm".to_string(),
- ];
- v8::V8::set_flags_from_command_line(argv);
+ " --no-wasm-async-compilation",
+ " --harmony-top-level-await",
+ " --harmony-import-assertions",
+ " --no-validate-asm",
+ );
+ v8::V8::set_flags_from_string(flags);
 }
 
 #[derive(Default)]