[lld] [lld] Support thumb PLTs (PR #86223)

[Fangrui Song via llvm-commits]

MaskRay wrote:



This Thumb PLT support is for very restricted use cases.
The lack of a MMU implies no sharing for the text segment used by two processes:

* Two processes running the same executable must have different data segments. The System V dynamic linking model requires a constant distance between the text segment and the data segment. Corollary: the text segment cannot be shared.
* Similarly, a shared object's text segment cannot be shared by two processes running different executables.

Perhaps the use case has a stronger requirement: no two executables (nanoapps?) are running at the same time.

It seems useful to update the description to clarify the case. The code generally looks good.

https://github.com/llvm/llvm-project/pull/86223