Hot Reload: fix new global not initialized

[yuxiaomao]

In the following code based on #145 , uncomment trace after launch will

• successfully print once after the first reload (4 changes detected: modified foo, entrypoint, new haxe.Log.formatOutput, haxe.Log.trace),
  • note that if we do not run any hl.Api.checkReload after the first reload, the program runs correctly.
• then read access violation after the second reload (2 changes detected, even no change on hl bytecode: new haxe.Log.formatOutput, haxe.Log.trace) at the beginning of foo(), probably global 2, 9 field 1,2[6] with global 9: haxe.$Log.

class Main {
	static var g1 = 0;
	static function foo() {
		// haxe.Log.trace("additional print"); // <- after launch, uncomment this line and save
		return 10000 + g1++;
	}

	static function reload() {
		Sys.sleep(1); // make sure timestamp is different
		Sys.command("haxe",["-hl","main.hl","-main","Main"]);
		Sys.println(hl.Api.checkReload() ? "Module Reloaded" : "Module not reloaded");
	}

	static function main() {
		while( true ) {
			var val = foo();
			Sys.println(val);
			reload();
		}
	}
}

When debugging, I saw that additional global values are forced reset in hl_module_patch every time memset(m2->globals_data+m1->globals_size,0,gsize - m1->globals_size) and are initialized by hl_module_init_constant(m2, c) and m2->functions_ptrs[c->entrypoint].
However, on the second reload, entrypoint function was not modified and is not called, leaving some global values to 0 (likely haxe.$Log, hl.CoreType, hl.CoreEnum).

This PR try to fix it by re-call the last entrypoint function.
(I think it does not work if no change is detected, for example if new functions are memorized by m1 in the future; but for now if a new type is added, there are likely some new functions)