[PATCH] g++: Add require-effective-target to multi-input file testcase pr95401.cc

[Patrick O'Neill <patrick@rivosinc.com>]

On non-vector targets dejagnu attempts dg-do compile for pr95401.cc.
This produces a command like this:
g++ pr95401.cc pr95401a.cc -S -o pr95401.s

which isn't valid (gcc does not accept multiple input files when using
-S with -o).

This patch adds require-effective-target vect_int to avoid the case
where the testcase is invoked with dg-do compile.

gcc/testsuite/ChangeLog:

	* g++.dg/vect/pr95401.cc: Add require-effective-target vect_int.

Signed-off-by: Patrick O'Neill <patrick@rivosinc.com>
---
Tested using rv64gc & rv64gcv to make sure the testcase runs/doesn't
compile as expected.

Somewhat related/similar problem (running vector test on non-vector
target):
https://inbox.sourceware.org/gcc-patches/20231102190911.66763-1-patrick@rivosinc.com/T/#u
https://inbox.sourceware.org/gcc-patches/20231102234527.77231-1-patrick@rivosinc.com/T/#u

Ideally we would have a way to ban a dejagnu dg-do or an equivalent to
check_vect_support_and_set_flags that returns true/false based on
if it emits run/compile as the default dg-do command.
require-effective-target seems to be a reasonable alternative.
pr95401.cc and pr95401a.cc only use int variables and arrays.
---
 gcc/testsuite/g++.dg/vect/pr95401.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/gcc/testsuite/g++.dg/vect/pr95401.cc b/gcc/testsuite/g++.dg/vect/pr95401.cc
index 6a56dab0957..6a1b65ff0e7 100644
--- a/gcc/testsuite/g++.dg/vect/pr95401.cc
+++ b/gcc/testsuite/g++.dg/vect/pr95401.cc
@@ -1,5 +1,6 @@
 // { dg-additional-options "-mavx2 -O3" { target avx2_runtime } }
 // { dg-additional-sources pr95401a.cc }
+// { dg-require-effective-target vect_int }
 
 extern int var_9;
 extern unsigned var_14;
-- 
2.34.1