Hi,

As PR103196 shows, p9-vec-length-full-7.c needs to be adjusted as the
complete unrolling can happen on some of its loops.  This patch is to
use pragma "GCC unroll 0" to disable all possible loop unrollings.
Hope it can help the case not that fragile.

There are some other p9-vec-length* cases, I noticed that some of them
use either bigger or unknown loop iteration counts, and
"p9-vec-length-3*" have considered the effects of complete unrolling.
So I just leave them alone for now.

Tested on powerpc64-linux-gnu P8 and powerpc64le-linux-gnu P9 and P10.

Is it ok for trunk?

BR,
Kewen
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	PR testsuite/103196

gcc/testsuite/ChangeLog:

	* gcc.target/powerpc/p9-vec-length-7.h: Add DO_PRAGMA macro.
	* gcc.target/powerpc/p9-vec-length-epil-7.c: Use unroll pragma to
	disable any unrollings.
	* gcc.target/powerpc/p9-vec-length-full-7.c: Remove useless option.
	* gcc.target/powerpc/p9-vec-length.h: Likewise.