Failures in test-http2-methods and test-http2-multiplex on ppc64el

https://autopkgtest.ubuntu.com/results/autopkgtest-kinetic/kinetic/ppc64el/n/nodejs/20220526_094438_1105e@/log.gz

Two tests are failing on just the ppc64el architecture, that seems to have appeared after updating to nghttp2/1.47.0-1, running tests against 12.22.9~dfsg-1ubuntu3.

not ok 1143 parallel/test-http2-methods
  ---
  duration_ms: 0.209
  severity: fail
  exitcode: 1
  stack: |-
    events.js:291
          throw er; // Unhandled 'error' event
          ^

    Error [ERR_HTTP2_STREAM_ERROR]: Stream closed with error code NGHTTP2_PROTOCOL_ERROR
        at ClientHttp2Stream._destroy (internal/http2/core.js:2212:13)
        at ClientHttp2Stream.destroy (internal/streams/destroy.js:38:8)
        at Http2Stream.onStreamClose (internal/http2/core.js:518:12)
    Emitted 'error' event on ClientHttp2Stream instance at:
        at emitErrorNT (internal/streams/destroy.js:92:8)
        at emitErrorAndCloseNT (internal/streams/destroy.js:60:3)
        at processTicksAndRejections (internal/process/task_queues.js:84:21) {
      code: 'ERR_HTTP2_STREAM_ERROR'
    }
  ...

not ok 1152 parallel/test-http2-multiplex
  ---
  duration_ms: 0.261
  severity: fail
  exitcode: 1
  stack: |-
    assert.js:101
      throw new AssertionError(obj);
      ^

    AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:
    + actual - expected

    + ''
    - 'abcdefghij'
        at ClientHttp2Stream.<anonymous> (/tmp/autopkgtest.vEXsJf/build.MYS/src/test/parallel/test-http2-multi\
plex.js:38:14)
        at ClientHttp2Stream.<anonymous> (/tmp/autopkgtest.vEXsJf/build.MYS/src/test/common/index.js:346:15)
        at ClientHttp2Stream.emit (events.js:314:20)
        at endReadableNT (_stream_readable.js:1241:12)
        at processTicksAndRejections (internal/process/task_queues.js:84:21) {
      generatedMessage: true,
      code: 'ERR_ASSERTION',
      actual: '',
      expected: 'abcdefghij',
      operator: 'strictEqual'
    }
  ...