[GlobalISel] Prefix MatchTable Lines with their Index (#125845)

I tried to keep it readable by making the width of the column with the
index always enough to contain the largest number.
That way things don't shift to the right every time a new digit appears,
it remains consistent.

Tests don't break because this only affects the beginning of the line
and FileCheck doesn't care about what comes before for the most part.

Example of the new output:
```
     /* 758359 */   // Label 9988: @758359
     /* 758359 */   GIM_Try, /*On fail goto*//*Label 9989*/ GIMT_Encode4(758435), // Rule ID 6715 //
     /* 758364 */     GIM_CheckConstantInt8, /*MI*/0, /*Op*/2, 0,
     /* 758368 */     // MIs[0] offset
```

Fixes #119177

0 files changed, 0 insertions, 0 deletions