In the first revision of Christophe Lyon's advsimd-intrinsics tests, 
https://gcc.gnu.org/ml/gcc-patches/2014-06/msg00532.html , both gcc-dg-runtest 
(to assemble only) and c-torture-execute were used. In review the gcc-dg-runtest 
part was then dropped, and execution tests continued using c-torture-execute. 
However, c-torture-execute ignores e.g. dg-options directives in the individual 
test files, whereas gcc-dg-runtest does not.

This patch switches to gcc-dg-runtest (with dg-do-what-default = "run") for all 
tests, allowing use of e.g. dg-options (in testsuite patch 3/3). This generally 
seems to work OK - indeed I also dropped the parallelization-disabling code - 
and the new advsimd-intrinsics.exp now follows gcc.c-torture/compile/compile.exp 
and gcc.c-torture/execute/execute.exp very closely. However, there are side 
effects, of which we should be aware, but with which I think we can live, 
specifically:

(1) the lines in the test log change from...

PASS: gcc.target/aarch64/advsimd-intrinsics/vcombine.c compilation,  -O1
PASS: gcc.target/aarch64/advsimd-intrinsics/vcombine.c execution,  -O1

...to...

PASS: gcc.target/aarch64/advsimd-intrinsics/vcombine.c   -O1  execution test

(that is, the compilation line disappears, but the (test for excess errors) 
remains unchanged)

(2) The "-Og -g" variant is no longer tested;  all of -O0, -O1, -O2, -O2 -flto 
-fno-use-linker-plugin -flto-partition=none, -O2 -flto -fuse-linker-plugin 
-fno-fat-lto-objects, -O3 -fomit-frame-pointer, -O3 -g, -Os still are. My 
feeling is that this set of options is exhaustive enough.

Cross-tested arm-none-eabi, aarch64-none-elf, aarch64_be-none-elf; natively 
tested arm-none-linux-gnueabihf and aarch64-none-linux-gnu.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/advsimd-intrinsics/advsimd-intrinsics.exp:
	Use gcc-dg-runtest.