[RS6000] dg-do !compile and scan-assembler

[RS6000] dg-do !compile and scan-assembler

These tests never checked assembly, because .s files were not
produced.  One was looking for the wrong instructions.

A typical error log
PASS: gcc.target/powerpc/vec-permute-ext-runnable.c (test for excess errors)
gcc.target/powerpc/vec-permute-ext-runnable.c output file does not exist
UNRESOLVED: gcc.target/powerpc/vec-permute-ext-runnable.c scan-assembler-times \\mpermx\\M 10

	* gcc.target/powerpc/vec-blend-runnable.c: Add save-temps.
	* gcc.target/powerpc/vec-insert-word-runnable.c: Likewise.
	* gcc.target/powerpc/vec-permute-ext-runnable.c: Likewise.
	* gcc.target/powerpc/vec-replace-word-runnable.c: Likewise.
	* gcc.target/powerpc/vec-splati-runnable.c: Likewise.
	* gcc.target/powerpc/vec-ternarylogic-3.c: Likewise.
	* gcc.target/powerpc/vec-ternarylogic-9.c: Likewise.
	* gcc.target/powerpc/vsx_mask-count-runnable.c: Likewise.
	* gcc.target/powerpc/vsx_mask-expand-runnable.c: Likewise.
	* gcc.target/powerpc/vsx_mask-extract-runnable.c: Likewise.
	* gcc.target/powerpc/vsx_mask-move-runnable.c: Likewise.
	* gcc.target/powerpc/vec-shift-double-runnable.c: Likewise,
	and correct assembly match.