Disable adjust line when emitting System Function

[nananapo]

issue

module test () {
    initial {

        $display("Hello World!");
    }
}

this code was translated into

module test_test ();
    initial begin
        $
        display("Hello World!");
    end
endmodule

what this PR changed

This bug is caused by adjusting line when emitting identifier after $.

veryl/crates/emitter/src/emitter.rs

Lines 376 to 379 in 2ee160a

	SymbolKind::SystemFunction => {
	self.str("$");
	self.identifier(&args[0]);
	}

veryl/crates/emitter/src/emitter.rs

Lines 176 to 180 in 2ee160a

	fn push_token(&mut self, x: &Token) {
	if self.adjust_line && x.line > self.line + 1 {
	self.newline();
	}
	self.adjust_line = false;

So I changed adjust_line to false when emitting system function.

[dalance]

Thank you for your contribution!
I'll merge this PR.