gdb: rework _active_linker_namespaces variable
This commit reworks the _active_linker_namespaces convenience variable
following Simon's feedback here:
https://sourceware.org/pipermail/gdb-patches/2025-August/219938.html
This patch implements the renaming to _linker_namespace_count (following
the standard set by _inferior_thread_count) and makes the convenience
variable more resilient in the multi-inferior case by providing a new
function, solib_linker_namespace_count, which counts gets the count of
namespaces using the solib_ops of the provided program_space
Approved-By: Simon Marchi <simon.marchi@efficios.com>
7 files changed
