[Bug target/87883] [ARM] ICE: Segmentation fault in arm_regno_class

[jozef.l at mittosystems dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87883

--- Comment #2 from Jozef Lawrynowicz <jozef.l at mittosystems dot com> ---
Created attachment 45074
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45074&action=edit
reg class checking patch

Hi Mihail,

Thanks for the info.

I fixed a bug for msp430-elf caused by REGNO_REG_CLASS and REG_CLASS_CONTENTS
being out of sync i.e. REGNO_REG_CLASS[reg] reported one class, but the bit for
that reg in that class was not set in REG_CLASS_CONTENTS.

So I was trying to add some generic warning to the middle-end which would catch
these cases for other targets (see attached patch). However, there were some
other issues with my proposal so I've parked it for now.

Given that I'm not going to proceed with my patch in its current state, it's up
to you whether to close this PR or not.

Kind regards,
Jozef