This patch implements a custom printer/parser for the immediate operand
of s_wait_alu that prints/parses the decoded counter values.
Format:
```
.<counter1>_<value1>_<counter2>_<value2>
```
Example:
`s_wait_alu .VaVdst_1_VmVsrc_1`
; Which is equivalent to this:
`s_wait_alu 8167`
Features:
- If a counter is at its maximum value it won't get printed.
- The parser will error out if a counter is greater or equal to its max
value.
- If all counters are disabled we can use 'AllOff'.
- For now we also accept numeric values for backwards compatibility with
older MIR.
Note: This is similar to https://github.com/llvm/llvm-project/pull/96004
but for `s_wait_alu`.
1658456ccf