[Bug testsuite/67450] New: [6 Regression] ERROR: can't unset "et_cache(ia32,value)": no such element in array

["hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67450

            Bug ID: 67450
           Summary: [6 Regression] ERROR: can't unset
                    "et_cache(ia32,value)": no such element in array
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: testsuite
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
                CC: clyon at gcc dot gnu.org
  Target Milestone: ---

r227401 added

proc check_cached_effective_target { prop args } {
    global et_cache
    global et_prop_list

    set target [current_target_name]
    if {![info exists et_cache($prop,target)]
        || $et_cache($prop,target) != $target} {
        verbose "check_cached_effective_target $prop: checking $target" 2
        set et_cache($prop,target) $target
        set et_cache($prop,value) [uplevel eval $args]
        lappend et_prop_list $prop
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

When $prop is already on et_prop_list, it leads to

ERROR: can't unset "et_cache(ia32,value)": no such element in array

in clear_effective_target_cache.

        verbose "check_cached_effective_target cached list is now:
$et_prop_list" 2
    }
    set value $et_cache($prop,value)
    verbose "check_cached_effective_target $prop: returning $value for
$target" 2
    return $value
}