Mostly from extra test cases, but also:
* Move the fgets size < 0 assertion into fgets.
* Use ELF aliases for strtoq/strtouq rather than duplicating code.
* Don't check uname() succeeded, since it can't fail.
Test: treehugger
Change-Id: I2e6b3b88b0a3eb16bd68be68b9bc9f40d8043291