[Bug target/95802] New: Duplicated login in host_detect_local_cpu and get_builtin_code_for_version

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95802

            Bug ID: 95802
           Summary: Duplicated login in host_detect_local_cpu and
                    get_builtin_code_for_version
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
                CC: crazylht at gmail dot com
  Target Milestone: ---

Both host_detect_local_cpu and get_builtin_code_for_version have similar
logic to deduce the target processor from processor family and available
ISAs.  They should be merged into one common logic.