LibWeb: SVG parse signed numbers in eliptical arc

Author: https://github.com/danners
Commit: f7dbcb652a
Pull-request: https://github.com/SerenityOS/serenity/pull/12632
Reviewed-by: https://github.com/AtkinsSJ ✅
Reviewed-by: https://github.com/IdanHo

Userland/Libraries/LibWeb/SVG/AttributeParser.h

@@ -70,6 +70,7 @@ private:
     void parse_comma_whitespace();
     float parse_fractional_constant();
     float parse_number();
+    float parse_nonnegative_number();
     float parse_flag();
     // -1 if negative, +1 otherwise
     int parse_sign();