fix: Check that the result of pcntl_waitpid is the PID of a managed process#1126

NanoSector wants to merge 7 commits intoPHPCSStandards:masterPHPCSStandards/PHP_CodeSniffer:masterfrom

NanoSector:bugfix/1112-check-waitpid-resultNanoSector/PHP_CodeSniffer:bugfix/1112-check-waitpid-resultCopy head branch name to clipboard