MFC r274075,r274581,r274582,r274595:

r274075 (by ngie):

Add reachover Makefiles for contrib/netbsd-tests/lib/libc; this adds approximately
500 new testcases

Various TODOs have been sprinkled around the Makefiles for items that even need
to be ported (missing features), testcases have issues with building/linking, or
issues at runtime.

A variant of this code has been tested extensively on amd64 and i386
10-STABLE/11-CURRENT for several months without issue. It builds on other
architectures, but the code will remain off until I have prove it works on
virtual hardware or real hardware on other architectures

In collaboration with: pho, Casey Peel <casey.peel@isilon.com>
Sponsored by: EMC / Isilon Storage Division

r274581 (by ngie):

Convert tools/regression/lib/libc/gen/test-arc4random into an ATF testcase and
rename as lib/libc/gen/arc4random_test

Sponsored by: EMC / Isilon Storage Division

r274582 (by ngie):

Remove test-arc4random from this Makefile so others can continue to use
this as-is for the time being

r274595 (by ngie):

Convert tools/regression/lib/libc/stdio/test-fpclassify into an ATF testcase and
Rename as lib/libc/stdio/fpclassify2_test

Sponsored by: EMC / Isilon Storage Division

Add reachover Makefiles for contrib/netbsd-tests/lib/libc; this adds approximately
500 new testcases

Various TODOs have been sprinkled around the Makefiles for items that even need
to be ported (missing features), testcases have issues with building/linking, or
issues at runtime.

A variant of this code has been tested extensively on amd64 and i386
10-STABLE/11-CURRENT for several months without issue. It builds on other
architectures, but the code will remain off until I have prove it works on
virtual hardware or real hardware on other architectures

In collaboration with: pho, Casey Peel <casey.peel@isilon.com>
Sponsored by: EMC / Isilon Storage Division