Names generated by @:generic conflict with manually declared names

[Ilir-Liburn]

Using previous sample

#8369

and adding

typedef Generic_Some = Generic<Some>;

makes compiler hanging if that module is imported to main module. Same for using.

[RealyUniqueName]

Reduced sample:

@:generic
class Generic<T> {}

typedef Generic_Int = Generic<Int>;

class Main {

	static function main():Void {}
}

Renaming typedef fixes the issue.
Generic<Int> generates a type named Generic_Int, which clashes with the name of the typedef.
Compiler hangs here:

haxe/src/typing/typeloadModule.ml

Lines 705 to 719 in a2f8c73

	let rec check_rec tt =
	if tt == t.t_type then error "Recursive typedef is not allowed" p;
	match tt with
	| TMono r ->
	(match !r with
	| None -> ()
	| Some t -> check_rec t)
	| TLazy f ->
	check_rec (lazy_type f);
	| TType (td,tl) ->
	if td == t then error "Recursive typedef is not allowed" p;
	check_rec (apply_params td.t_params tl td.t_type)
	| _ ->
	()
	in

This is not a regression. Reproduces on 3.4.7

[RealyUniqueName]

Related discussion: #6969 (comment)

[RealyUniqueName]

Made @:generic to emit an error if it generates a name, which is already used.

Leaving this issue open because I beleave we need to find a way to not generate conflicts with user-written code.

[nadako]

we need to find a way to not generate conflicts with user-written code.

we have a soft-reserved _hx_ prefix for that, so maybe we should just use that