Ensure clang and icc builds are also ok with the new ixx/oxx/vxx

[valassi]

Ensure clang and icc builds are also ok with the new ixx/oxx/vxx

This is a reminder for myself. The MR #723 fixing #701 introduces some explicit attributes to disable auto vectorization. I tested this in gcc, I need to test that in clang and icx.

[valassi]

As described in #727 , I have chosen a new strategy to fix #701 in MR #723. The new strategy does not use any pragmas. Therefore I believe that there is nothing special to do.

Still keep this open - should check that #723 builds and tests ok also on clang and icc.

[valassi]

Note: MR #737 has fixed several new FPE issues due to the upgrade from icx 2023.1 to 2023.2, see #736. This is part of a general test of new compilers in #734.