Remove unused GETFIELD/SETFIELD helpers

[EgorBo]

Also, JIT used to pretend that CORINFO_HELP_UNBOX_NULLABLE returned a TYP_STRUCT and had some special handling around multi-reg return. While in fact the helper is VOID

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[EgorBo]

@MihuBot

[jakobbotsch]

Also, JIT used to pretend that CORINFO_HELP_UNBOX_NULLABLE returned a TYP_STRUCT and had some special handling around multi-reg return. While in fact the helper is VOID

This is actually an optimization done by the importer. It avoids introducing unnecessary copies by passing the address of the store destination of the unbox operation directly as the address to the helper call, in the same way as return buffers from regular calls are handled.

I'm fine with simplifying all of this, especially if it's going to be on the cold path, just wanted to add some context and add it here for posterity.

[EgorBo]

Also, JIT used to pretend that CORINFO_HELP_UNBOX_NULLABLE returned a TYP_STRUCT and had some special handling around multi-reg return. While in fact the helper is VOID

This is actually an optimization done by the importer. It avoids introducing unnecessary copies by passing the address of the store destination of the unbox operation directly as the address to the helper call, in the same way as return buffers from regular calls are handled.

I'm fine with simplifying all of this, especially if it's going to be on the cold path, just wanted to add some context and add it here for posterity.

Yeah it's understandable, I presume it's better to use a separate node/GT_INTRINSIC for such case to avoid dealing with ABI stuff too early?

Here are the SPMI diffs on win-x64 (although, I couldn't download libraries.pmi.tests collection): https://gist.github.com/EgorBo/6d6f29c571b09f058ab3f2f80ba6e70a not too bad IMO

[EgorBo]

@jakobbotsch does the jit part look good otherwise? I've applied the lvHasLdAddrOp fix

[jakobbotsch]

LGTM, nice clean up!