[Bug middle-end/90367] Spurious warning array subscript is above array bounds

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90367

--- Comment #11 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Changing DenseMapBase's
  ValueT &operator[](const KeyT &t)
To:

{
    const KeyT Key = t;
    return FindAndConstruct(Key).second;
  }


This will cause the warning to go away.  
This comes from:
RemapSwizzle[i] = ....

On a few lines.
GCC does not know that FindAndConstruct does not change the value of its
argument or the argument escapes.