ee_core: poll IGR without VBLANK interrupt

[L10N37]

Confirmed results

These titles, along with a handful of others, were tested with the new
alarm-driven IGR implementation and Compatibility Mode 6 disabled.

Fatal Fury: Battle Archives Volume 2

• Serial: SLUS-21723
• Region/video standard: NTSC
• Loading method: SMB
• Passes the previous black-screen location
• Gameplay works
• IGR works
• Successfully returns to the configured exit ELF
• Confirmed on PCSX2 and real PlayStation 2 hardware

Ratchet & Clank 3

• Serial: SCUS-97353
• Region/video standard: NTSC
• Loading method: SMB
• Game launches and plays normally
• IGR works
• Successfully returns to the configured exit ELF
• Confirmed on real PlayStation 2 hardware

Ocean Commander

• Serial: SLES-55047
• Region/video standard: PAL
• Loading method: SMB
• Game launches and plays normally
• IGR works
• Successfully returns to the configured exit ELF
• Confirmed on real PlayStation 2 hardware

These tests provide successful real-hardware coverage of both NTSC and
PAL software.

Further testing requested

Testing would still be useful with:

• additional libpad and libpad2 titles
• games that replace or reload their main ELF
• repeated launch and IGR cycles
• HDD, USB, MX4SIO and other loading methods
• additional fat and slim console revisions
• power-button handling
• GSM, PS2RD cheats and IGS builds
• games already known to have unusual IGR behaviour

[NathanNeurotic]

@L10N37 is this the one you wanted me to add?

[L10N37]

Might need more testing, there's ratchet and clank 3 SMB fix too. Games that needed mode 6 likely won't anymore with this but haven't thoroughly tested.