[Bug target/82990] Add -mprefer-vzeroupper

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82990

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
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  Attachment #42608|0                           |1
        is obsolete|                            |

--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> ---
Created attachment 42611
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42611&action=edit
A better patch

Sebastian, please take a look.