[llvm] [BOLT] Support instrumentation hook via DT_INIT_ARRAY (PR #167467)

[Paschalis Mpeis via llvm-commits]

https://github.com/paschalis-mpeis commented:

Hey @vleonen,

I get some lit errors on the below regex (lines 90, 113, 163 in `hook-init.s`):
```js
{{0+}}[[#%x, EP_ADDR]] {{.*}} __bolt_runtime_start
```


Probably the row number is not matching?
```
    23: 0000000000123abc     0 NOTYPE  WEAK   DEFAULT   ABS __bolt_runtime_start
```

https://github.com/llvm/llvm-project/pull/167467