Tests/RunCMake/IAR: ASM cases fail on Windows
!9797 enables IAR testing in some CI jobs on Windows, but leaves out coverage of the ASM language because it does not work:
```
C:\...\avr\bin\aavr.exe -S "C:\...\Tests\RunCMake\IAR\module.asm" -o CMakeFiles\exec-asm.dir\module.r90
SECTION CSTACK:DATA:NOROOT(4)
--------^
"C:\...\Tests\RunCMake\IAR\module.asm",32 Error[40]: Bad instruction
SECTION `.cstartup`:CODE(2)
--------^
"C:\...\Tests\RunCMake\IAR\module.asm",33 Error[40]: Bad instruction
```
issue