MFC loader+userland TSLOG support
stand/common: Add file_addbuf()
libsa: Add support for timestamp logging (tslog)
stand/common: Add support for timestamp logging (tslog)
i386/loader: Call tslog_init
efi/loader: Call tslog_init (+ bugfix)
stand/common command_boot: Pass tslog to kernel
kern_tslog: Include tslog data from loader
loader: Use tslog to instrument some functions
Add userland boot profiling to TSLOG (+ bugfix)
Sponsored by: https://www.patreon.com/cperciva
(cherry picked from commit 60a978bec9123fcb9c74bd925e06dd3f4faddac6)
(cherry picked from commit e193d3ba337757a27148a38494d3df106b826d1c)
(cherry picked from commit c8dfc327db2373c721a35efe857cf07262fd7dd0)
(cherry picked from commit c4b65e954f0f4754941f5b37436231f611b76d67)
(cherry picked from commit f49381ccb6bc8a5733f1aa505e716eddae299986)
(cherry picked from commit 537a44bf281559d304850b5e28b6f8b8e44fd593)
(cherry picked from commit fe51b5a76de38d20cddc05a4c6cb1103d1a0547e)
(cherry picked from commit 313724bab940c1844fda3d797cf88cd46780e62a)
(cherry picked from commit 46dd801acb2318c8464b185893bb111f09b71138)
(cherry picked from commit 52e125c2bd302982c179ecc920cc9a6e166033d6)
(cherry picked from commit 19e4f2f289fb8d2b14576a65ca9e6f931dbb6a02)