Function matrix

tests/TestExtra.cpp:149–151

{\r\n\
    float[] arr;\r\n\
    int width, height;\r\n\
}\r\n\
matrix matrix(int width, height){ matrix ret; ret.arr = new float[width * height]; ret.width = width; ret.height = height; return ret; }\r\n\
class row\r\n\
{\r\n\
    matrix ref parent;\r\n\