[RFC/RFT] Tree-level lowering of generic vectors (take 2)

[Yossi Markovich]

>If anyone would like to test it on one of the affected targets, especially
PowerPC, that >would be good; note that this patch depends on the one at
>http://gcc.gnu.org/ml/gcc-patches/2004-07/msg01329.html

We tested your two last patches on powerpc-apple-darwin7.0.0.
Bootstrap passed successfully, but there were a few of regressions when
running 'make -k check'

in gcc
FAIL: gcc.c-torture/execute/simd-2.c execution,  -O3 -fomit-frame-pointer
FAIL: gcc.c-torture/execute/simd-2.c execution,  -O3 -g
FAIL: gcc.dg/darwin-abi-2.c execution test
in g++
FAIL: g++.dg/ext/altivec-3.C execution test

By the way, there were a few improvements two (tests that used to fail and
now pass)

in gcc
FAIL: gcc.dg/compat/vector-1 c_compat_x_tst.o compile
FAIL: gcc.dg/compat/vector-1 c_compat_y_tst.o compile
in g++
FAIL: g++.dg/eh/simd-2.C (test for excess errors)
FAIL: g++.dg/parse/attr2.C (test for excess errors)

Yossi