[scudo] Add errno description to mmap failure. (#87713)

Added unit tests for all of the linux report error functions.

GitOrigin-RevId: 0a39f1a7e5c7fd00b37231964ec81dae938948e7
Change-Id: Ieea9cecbe6dcf6aff9d65392b220583a1a2504e4
2 files changed