[llvm] [ARM] Pattern match Low Overhead Loops pseudos (NFC) (PR #168209)

[Vladi Krapp via llvm-commits]

VladiKrapp-Arm wrote:

@s-barannikov :
After this patch was merged we started getting compilation failures when building 
https://github.com/ARM-software/CMSIS-DSP/blob/main/Source/MatrixFunctions/arm_mat_inverse_f64.c

Reproducer: 
https://godbolt.org/z/89f8179h5
(Mostly reduced, but I'll try to create an even smaller IR reproducer)


Possibly the change to use TableGen is missing some additional element that needs handling?

https://github.com/llvm/llvm-project/pull/168209