mingw fixes: drop gettimeofday(), fix bitrot caused by untested commits in cacheline.c, fix MOWGLI_OS_WIN mispelled as MOWGLI_OS_WINDOWS

...h is in modern mingw32.

Also fixes missing s/SLPI/SYSTEM_LOGICAL_PROCESSOR_INFORMATION/ and a
missing variable rename in Windows-specific cacheline code. Fixes
mistaken use of MOWGLI_OS_WINDOWS instead of MOWGLI_OS_WIN.

Dropping gettimeofday() fixes type collision of “struct timezone” with
the compat type provided by mingw32.