runtime: add crash stack support for wasm

Currently if morestack on g0 happens the wasm runtime prints
"RuntimeError: memory access out of bounds", which is quite misleading.
By switching to a crash stack we can get better stacktraces
for the error.

There is no way to automate tests for this feature on wasm, since
TestG0StackOverflow relies on spawning a subprocess which is not
supported by the wasm port.

The way I got this tested manually is to comment everything in
TestG0StackOverflow, leaving just runtime.G0StackOverflow().

Then it is a matter of invoking the test:

    GOOS=js GOARCH=wasm go test runtime -v -run=TestG0StackOverflow

Change-Id: If450f3ee5209bb32efc1abd0a34b1cc4a29d0c46
GitHub-Last-Rev: 0d7c396e4cfeadc1188cae2b55661af10c8189e7
GitHub-Pull-Request: golang/go#63956
TryBot-Result: Gopher Robot <>
Reviewed-by: David Chase <>
Run-TryBot: Cherry Mui <>
Reviewed-by: Cherry Mui <>
3 files changed
tree: 49fe39dc8fef7589184225aec6c142b05e78f8d4
  1. .github/
  2. api/
  3. doc/
  4. lib/
  5. misc/
  6. src/
  7. test/
  8. .gitattributes
  9. .gitignore
  10. codereview.cfg
  12. go.env

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