fixes for updated analyzer and unused references

std/hl/_std/EReg.hx

@@ -53,8 +53,7 @@ private typedef ERegValue = hl.types.NativeAbstract<"ereg">;
 	}
 
 	public function matchedLeft() : String {
-		var len = 0;
-		var p = regexp_matched_pos(r,0,len);
+		var p = regexp_matched_pos(r,0,null);
 		return last.substr(0,p);
 	}
 

std/hl/_std/String.hx

@@ -173,8 +173,7 @@ class String {
 	}
 
 	function toUtf8() : hl.types.Bytes {
-		var size = 0;
-		return bytes.utf16ToUtf8(0, size);
+		return bytes.utf16ToUtf8(0, null);
 	}
 
 	@:keep function __string() : hl.types.Bytes {

std/hl/_std/Sys.hx

@@ -39,8 +39,7 @@ class Sys {
 		utf8Path = sys_utf8_path();
 	}
 	static function getPath( s : String ) : hl.types.Bytes {
-		var size = 0;
-		return utf8Path ? s.bytes.utf16ToUtf8(0, size) : s.bytes;
+		return utf8Path ? s.bytes.utf16ToUtf8(0, null) : s.bytes;
 	}
 	static function makePath( b : hl.types.Bytes ) : String {
 		return utf8Path ? String.fromUTF8(b) : String.fromUCS2(b);
@@ -97,8 +96,7 @@ class Sys {
 	}
 
 	public static function setTimeLocale( loc : String ) : Bool {
-		var size = 0;
-		return set_time_locale(loc.bytes.utf16ToUtf8(0,size));
+		return set_time_locale(loc.bytes.utf16ToUtf8(0,null));
 	}
 
 	public static function getCwd() : String {

std/hl/_std/sys/io/File.hx

@@ -27,8 +27,7 @@ typedef FileHandle = hl.types.NativeAbstract<"hl_fdesc">;
 @:coreApi class File {
 
 	public static function getContent( path : String ) : String {
-		var size = 0;
-		var bytes = file_contents(Sys.getPath(path), size);
+		var bytes = file_contents(Sys.getPath(path), null);
 		if( bytes == null ) throw new Sys.SysError("Can't read "+path);
 		return @:privateAccess String.fromUTF8(bytes);
 	}

std/hl/_std/sys/net/Host.hx

@@ -29,9 +29,8 @@ class Host {
 	public var ip(default,null) : Int;
 
 	public function new( name : String ) : Void {
-		var size = 0;
 		host = name;
-		ip = host_resolve(@:privateAccess name.bytes.utf16ToUtf8(0,size));
+		ip = host_resolve(@:privateAccess name.bytes.utf16ToUtf8(0,null));
 		if( ip == -1 ) throw new Sys.SysError("Unresolved host " + name);
 	}