[Ada] Fix Vector_Alignment setting

[Arnaud Charlet <charlet at adacore dot com>]

Tested on i686-linux, committed on trunk

VECTOR_ALIGMENT is used to set the alignment of vector datatypes in both the
hard and the soft binding implementations.
It is just right for the hard binding as Maximum_Alignment is expected
to be 16 for the real Altivec ABI.
It is upper-bounded by Standard'Maximum_Alignment for the soft binding,
which doesn't require strict 16bytes alignment and is expected to work
on targets where such an alignment cannot be enforced.
It is lower-bounded by 16 also for the soft binding, to avoid useless
and space inefficient overalignment on targets where Maximum_Alignment
is larger.

2006-02-13  Olivier Hainque  <hainque@adacore.com>

	* g-altive.ads (VECTOR_ALIGNMENT): Set to Min (16, Max_Alignment),
	to avoid useless and space inefficient overalignments on targets where
	Max_Alignment is larger than 16.

Attachment: difs.52
Description: Text document