Missing tests for ESC opcodes D9, DA, DB, DC, DD, DE, DF

[Octocontrabass]

I would expect DF E0 (FNSTSW AX) to behave differently from D8 E0 (FSUB ST(0)), but I can't check because it isn't included in any tests.

The undocumented opcodes might have interesting behavior too.

[dbalsom]

To clarify are you just asking for tests of ESC without an FPU?

[Octocontrabass]

Correct. As far as I know, the unique behavior of FNSTSW AX should still be visible without an FPU.

[Octocontrabass]

Wow, I should have waited until after Michal Necasek wrote this blog post.

[dbalsom]

I saw that. One of the other good reasons I didn't include ESC opcodes is because none of the FPU-related pins were even hooked up :D