unstdify macros

[vilasfe]

A commit about 2 months ago to the mdspan repo renamed several macros from _MDSPAN_XXXX to MDSPAN_IMPL_XXXX, which causes breakage during the autodownload of that library and building the stdBLAS examples. This commit updates the stdBLAS macros to match the new names.

[mhoemmen]

@vilasfe Hi! Thanks for your contribution! This looks like your first to this repository. Could you please e-mail me to confirm your identity? Thanks!

[vilasfe]

@mhoemmen I see the errors and for some reason they didn't show up on my local build. I can fix them tomorrow morning

I'll look for your email address in your profile tomorrow too, so I can confirm my identity for you. I'll let you know if I can't find it

[vilasfe]

I tried emailing the address I found for you in the code, but it got rejected for some reason. But I at least was able to amend my commits to match my email to my GPG key so it will show them as verified now. Hope that helps.

[vilasfe]

synchronized with current main branch

[mhoemmen]

E-mail confirmed (thanks!). It looks like the changes have already been applied. How shall we proceed? I recommend closing the PR.

[vilasfe]

yep, it looks like in the time since I posted this, the changes are all merged, so now it says 0 files changed

Closing since no longer needed.

[mhoemmen]

@vilasfe Thanks for reaching out and for offering a fix! : - )