[llvm] MCFragment: Use trailing data for fixed-size part (PR #150846)

[Fangrui Song via llvm-commits]

MaskRay wrote:

minuscule instructions:u decrease

https://llvm-compile-time-tracker.com/compare.php?from=85213f2f884cd68586723163629474a8eea46a74&to=847901f5d28cc25ead3183c6b08b3d6840d3ac95&stat=instructions:u

(Is there a convenient way to generate markdown from the HTML code? The link may be dead in the future and we ought to paste a markdown. For now I am using https://jmalarcon.github.io/markdowntables/ )

|Benchmark|Old|New|
|--- |--- |--- |
|kimwitu++|22211M|22209M (-0.01%)|
|sqlite3|3944M|3948M (+0.10%)|
|consumer-typeset|11003M|11001M (-0.02%)|
|Bullet|58147M|58092M (-0.09%)|
|tramp3d-v4|18668M|18629M (-0.21%)|
|mafft|5891M|5889M (-0.03%)|
|ClamAV|12101M|12092M (-0.08%)|
|lencod|11149M|11141M (-0.07%)|
|SPASS|12719M|12706M (-0.10%)|
|7zip|128392M|128305M (-0.07%)|
|geomean|16341M|16332M (-0.06%)|


https://github.com/llvm/llvm-project/pull/150846