cmd/link,runtime: unused fields in `inlinedCall`

[prattmic]

runtime.inlinedCall fields parent (parentPc is used instead), file (pcfile in the parent is used), and line (pcln in the parent is used) seem to be completely unused. They are a reflection of fields in goobj.InlTreeNode, which are used within the toolchain, but the runtime itself doesn't need them.

If I did the math right, cmd/go contains 431KB of inlineTree objects (2.8% of the binary size). With those fields gone it would drop to 258KB.

[aclements]

Neat. Originally these were important because we didn't have parentPc or the marker NOPs to attach file/line to, so the only source of that metadata was the inline tree. I believe you're right that they are no longer necessary.

[gopherbot]

Change https://go.dev/cl/427960 mentions this issue: cmd/link,runtime: remove unused fields from inlinedCall