deno_core::JsRuntime should have separate method for executing "non-main" module

[bartlomieju]

In test_runner.rs there's:

deno/cli/tools/test_runner.rs

Lines 302 to 308 in 76d3430

	let execute_result = worker.execute_module(&main_module).await;
	execute_result?;
	worker.execute("window.dispatchEvent(new Event('load'))")?;
	let execute_result = worker.execute_module(&test_module).await;
	execute_result?;

This leads to a quirk where both main_module and test_module would return true if import.meta.main was checked inside those modules. This is a bug in module loading implementation in deno_core, where JsRuntime::execute_module() treats entry-point as a "main" module.

This should be fixed by providing a second method (JsRuntime::execute_main_module()) that should be used for top-level module and JsRuntime::execute_module() should be used for executing other modules that are not top-level.