RTS GetTime.c is broken on Darwins that include clock_gettime

GHC fails to build on versions of Darwin which include clock_gettime.

On Darwin versions which include clock_gettime, the #ifdefs are structured to prefer using clock_gettime over the mach-specific time functions and structs; however, a couple of places in GetTime.c use the mach functions unconditionally even though the mach/mach_time.h header won't be included if clock_gettime is available.

The attached patch fixes this by checking HAVE_CLOCK_GETTIME first before checking if the OS is Darwin.

Trac metadata

Trac field	Value
Version	8.0.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system	Unknown/Multiple
Architecture	Unknown/Multiple