[gcc r17-3503] testsuite: Select SVE2 for the aarch64_sve2_hw probe

https://gcc.gnu.org/g:5900e859fbd0ca39d81a275bcc7c96814c0606e1

commit r17-3503-g5900e859fbd0ca39d81a275bcc7c96814c0606e1
Author: Kyrylo Tkachov <[email protected]>
Date:   Wed Aug 19 11:54:14 2026 +0200

    testsuite: Select SVE2 for the aarch64_sve2_hw probe
    
    check_effective_target_aarch64_sve2_hw compiles its probe program with
    no architecture options, so the assembler rejects the SVE2 instruction
    in the inline asm unless the toolchain already defaults to SVE2.  The
    check then reports 0 even on SVE2 hardware and every test that requires
    it is skipped.
    
    Select SVE2 for the probe with a target pragma, the way
    check_effective_target_aarch64_sve2p1_hw already does.  On a Neoverse V2
    host this turns gcc.target/aarch64/sve2/pr122069_2.c and
    gcc.target/aarch64/sve2/pr123775.c from UNSUPPORTED into PASS.
    
    Bootstrapped and tested on aarch64-none-linux-gnu.
    
    gcc/testsuite/ChangeLog:
    
            * lib/target-supports.exp
            (check_effective_target_aarch64_sve2_hw): Add a target pragma to
            the probe program.
    
    Signed-off-by: Kyrylo Tkachov <[email protected]>

Diff:
---
 gcc/testsuite/lib/target-supports.exp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
index 13a269100941..5beec1c45ebc 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -6793,6 +6793,7 @@ proc check_effective_target_aarch64_sve2_hw { } {
 	return 0
     }
     return [check_runtime aarch64_sve2_hw_available {
+	#pragma GCC target "+sve2"
 	int
 	main (void)
 	{