runtime: "invalid pc-encoded table" throw caused by bad cgo traceback [1.15 backport]

[gopherbot]

@prattmic requested issue #44971 to be considered for backport to the next 1.15 minor release.

@gopherbot please open backport for 1.16 and 1.15. The only workaround is to change the C traceback engine, which isn't usually feasible.

[gopherbot]

Change https://golang.org/cl/305890 mentions this issue: [release-branch.go1.15] runtime: non-strict InlTreeIndex lookup in Frames.Next

[dr2chase]

Sometimes, people using cgo get useless stack traces, and there is no workaround; approving for next dot release.

[gopherbot]

Closed by merging a07f9d2 to release-branch.go1.15.