Fix vect-simd-clone testcase dump scanning

Fix vect-simd-clone testcase dump scanning

This replaces i686*-*-* && { ! lp64 } with the appropriate
{ i?86-*-* x86_64-*-* } && { ! lp64 } for the testcases and
also amends the e variants checking last variant for avx.
I've used avx in the dump scanning, not avx_runtime, since
the dumps get produced when one would not execute but only
compile them.  The f varaints lack AVX checking, I didn't
rectify this with this patch.

	* gcc.dg/vect/vect-simd-clone-16e.c: Fix x86 lp64 checking
	and add missing avx guard.
	* gcc.dg/vect/vect-simd-clone-17e.c: Likewise.
	* gcc.dg/vect/vect-simd-clone-18e.c: Likewise.
	* gcc.dg/vect/vect-simd-clone-16f.c: Fix x86 lp64 checking.
	* gcc.dg/vect/vect-simd-clone-17f.c: Likewise.
	* gcc.dg/vect/vect-simd-clone-18f.c: Likewise.