Update the constants associated with the evaluation of j0f(x)
for |x| small.

While here, remove the explicit cast of 0.25 to float.  Replace
a multiplication involving 0.25 by a division using an integer
constant 4.  Make a similar change in j0() to minimize the diff.

Suggested by:	bde
Add missing END macros to some of the xscale functions.

MFC after:	1 week
Sponsored by:	ABT Systems Ltd
Use the unified syntax in a few more assembly files

MFC after:	1 week
Sponsored by:	ABT Systems Ltd
Set the alignment to 4-bytes after a string as clang 3.5 can switch to
thumb mode if this is incorrect.

MFC after:	1 week
Sponsored by:	ABT Systems Ltd
Place the literal pool after a RET otherwise clang 3.5 tries to put it too
far away from a ldr psuedo instruction. With this clang will place the
literal value here where it's close enough to be loaded.

MFC after:	1 week
Sponsored by:	ABT Systems Ltd
Switch to an armv6k cpu, without this clang 3.5 complains "bx lr" is
unsupported as it needs a newer cpu.

MFC after:	1 week
Sponsored by:	ABT Systems Ltd