[Bug target/126672] New: tbx({0},table, idxs) ->tbl(table, idxs)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126672

            Bug ID: 126672
           Summary: tbx({0},table, idxs) ->tbl(table, idxs)
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Keywords: easyhack, missed-optimization
          Severity: enhancement
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---
            Target: aarch64

Created attachment 65253
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=65253&action=edit
testcase

TBX with all zero input is the same as TBL.
That is because TBL uses zero if the value is out of range while TBX uses the
value of the input.