Merge branch '6.4' into 7.1

* 6.4:
  [Process] minor fix
  [Process] Fix finding executables independently of open_basedir
  [HttpKernel] Skip logging uncaught exceptions in ErrorHandler, assume $kernel->terminateWithException() will do it
  parse empty sequence elements as null

Author: nicolas-grekas

CHANGELOG.md

@@ -12,7 +12,6 @@ CHANGELOG
  * Add `PhpSubprocess` to handle PHP subprocesses that take over the
    configuration from their parent
  * Add `RunProcessMessage` and `RunProcessMessageHandler`
- * Support using `Process::findExecutable()` independently of `open_basedir`
 
 5.2.0
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