Add MIR_SWITCH insn description.
| `MIR_BF` | 2 | jump to the label when 2nd **64-bit** operand is **zero** |
| `MIR_BFS` | 2 | jump to the label when 2nd **32-bit** operand is **zero** |
+### MIR switch insn
+ * The first operand of `MIR_SWITCH` insn should have an integer value from 0 to `N - 1` inclusive
+ * The rest operands should be `N` labels, where `N > 0`
+ * Execution of the insn will be an jump on the label corresponding to the first operand value
+ * If the first operand value is out of the range of permitted values, the execution result is undefined
+
### MIR integer comparison and branch insn
* The first operand of the insn should be label. Label will be the next executed insn if the result of comparison is non-zero
