mir2c bug with floating point

[Pombal]

When outputting a whole number for MIR_OP_FLOAT on out_op(), mir2c outputs something like 3f. This doesn't compile.

Using a specification such as "%#.*gf" would solve the issue.

[vnmakarov]

Thank you for reporting this bug. I've fixed it by https://github.com/vnmakarov/mir/commit/73057e24f0e0bbd2c5ee6770261370d7ff71da4e