Describe -O<n> option.
checking of C files without MIR code generation
* Option `-pedantic` is used for stricter diagnostic about C
standard conformance. It might be useful as C2MIR implements some GCC extensions of C
+ * Option `-O<n>` is used to set up MIR-generator optimization level. The optimization levels are described
+ in documentation fo MIR generator API function `MIR_gen_set_optimize_level`
* Option `-dg` is used for debuging MIR-generator. It results in dumping debug information
about MIR-generator work to `stderr`
* Besides C files, MIR textual files with suffix `.mir` and MIR
