src: fix build on certain platforms

The `double` fields in `performance_state` could previously have
been aligned at 4-byte instead of 8-byte boundaries, which would
have made creating an Float64Array them as a array buffer view
for an ArrayBuffer extending over the entire struct an invalid
operation.

Ref: 67269fd7

Comments out related flaky failure

PR-URL: https://github.com/nodejs/node/pull/14996


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>