ZJIT: Optimize NewArray to use rb_ec_ary_new_from_values (fixes #829)

[goshanraj-g]

Fixes #829

Instead of calling rb_ary_new_capa and rb_ary_push for each element (this is N+1 C function calls), this uses gen_push_opnds and calls rb_ec_ary_new_from_values once, which matches what the interpreter and YJIT do