Integrate:

Integrate:
[ 32483]
Use a new (clean) anonymous hash for each loop, rather than a hash in
the pad, as the latter can change internal state sufficiently to
confuse matters (even though in all cases it has no keys and from
Perl space is "measurably" identical).

[ 32500]
Get APItest.xs compiling on 5.8.x by making the compilation of the
Perl_hv_common() test code conditional on the macro hv_common being
defined, and the refcounted_he code conditional on it being 5.9 or
later.

[ 32501]
Hack round the fact that UNITCHECK is nothing special on 5.8.x by
conditionally creating a sub UNITCHECK(&);

[ 32502]
UNITCHECK isn't anything special in 5.8.x, so don't run those tests.

[ 32503]
Skip the op.t API test as it's not relevant to 5.8.x (%^H propagation).
Correct the expectations of hash.t and svsetsv.t for 5.8.x.

[ 32507]
Test both dMY_CXT and dMY_CXT_INTERP.
p4raw-link: @32507 on //depot/blead-maint-fixup/perl: 948cafa0ee2c83e155ea7f64aa3684aa54c83031
p4raw-link: @32503 on //depot/blead-maint-fixup/perl: 0a4679392d1fb21a111f1f0a9e93261b2b2cd4e7
p4raw-link: @32502 on //depot/blead-maint-fixup/perl: cfed56ecfc9c769a0f76147400aa46972ddbb0be
p4raw-link: @32501 on //depot/blead-maint-fixup/perl: 8221ebfdedcb3fbfc645196464faaf397ba18800
p4raw-link: @32500 on //depot/blead-maint-fixup/perl: 77ea6e921df11217724b2f5c3c6b6a6ff488ab44
p4raw-link: @32483 on //depot/blead-maint-fixup/perl: 42b4d13769a3b10e7ffb0a3d275d2fdda0245bd5

p4raw-id: //depot/perl@32699
p4raw-integrated: from //depot/blead-maint-fixup/perl@32698 'copy in'
	ext/XS/APItest/APItest.pm ext/XS/APItest/APItest.xs
	ext/XS/APItest/t/hash.t ext/XS/APItest/t/my_cxt.t
	ext/XS/APItest/t/op.t ext/XS/APItest/t/svsetsv.t
	ext/XS/APItest/t/xs_special_subs.t
	ext/XS/APItest/t/xs_special_subs_require.t (@32482..) 'merge
	in' perl.h (@32504..)