redox: relax type requirement for tv_nsec, fixing x86 32-bit #150

# to view logs

Job	Run time
Rustfmt	3s
Build for Android and Redox (x86_64-linux-android)	6s
Publish Documentation	20s
Build for Android and Redox (x86_64-unknown-redox)	8s
Test (stable)	12s
Test (beta)	15s
Test (nightly)	11s
Test (macos)	10s
Test (win32)	32s
Test (win64)	36s
Test (mingw)	29s
	3m 2s

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