std: Disable some vector-related tests for hexagon.

See:

* llvm/llvm-project#118879
* llvm/llvm-project#134659

Author: alexrp

lib/std/mem.zig

@@ -431,7 +431,9 @@ test zeroes {
     }
     try testing.expectEqual(@as(@TypeOf(b.vector_u32), @splat(0)), b.vector_u32);
     try testing.expectEqual(@as(@TypeOf(b.vector_f32), @splat(0.0)), b.vector_f32);
-    try testing.expectEqual(@as(@TypeOf(b.vector_bool), @splat(false)), b.vector_bool);
+    if (!(builtin.zig_backend == .stage2_llvm and builtin.cpu.arch == .hexagon)) {
+        try testing.expectEqual(@as(@TypeOf(b.vector_bool), @splat(false)), b.vector_bool);
+    }
     try testing.expectEqual(@as(?u8, null), b.optional_int);
     for (b.sentinel) |e| {
         try testing.expectEqual(@as(u8, 0), e);

lib/std/simd.zig

@@ -464,6 +464,7 @@ test "vector prefix scan" {
     if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
     if ((builtin.cpu.arch == .armeb or builtin.cpu.arch == .thumbeb) and builtin.zig_backend == .stage2_llvm) return error.SkipZigTest; // https://github.com/ziglang/zig/issues/22060
     if (builtin.cpu.arch == .aarch64_be and builtin.zig_backend == .stage2_llvm) return error.SkipZigTest; // https://github.com/ziglang/zig/issues/21893
+    if (builtin.zig_backend == .stage2_llvm and builtin.cpu.arch == .hexagon) return error.SkipZigTest;
 
     if (builtin.cpu.arch.isMIPS()) return error.SkipZigTest;