[llvm-readobj][ARM] - Improve support of printing unwind (-u) information for...

[llvm-readobj][ARM] - Improve support of printing unwind (-u) information for non-relocatable objects.

This is the one more patch for https://bugs.llvm.org/show_bug.cgi?id=47581

It fixes how we print an information for the Generic model. With this patch
we are able to read values from `.ARM.extab` and dump proper personality routines names/addresses.

Differential revision: https://reviews.llvm.org/D88478