[SYCL][E2E] Disable two AtomicRef tests on HIP AMD (#15792)

Sporadically failing

Signed-off-by: Sarnie, Nick <nick.sarnie@intel.com>

Author: sarnex

sycl/test-e2e/AtomicRef/assignment_atomic64_generic.cpp

@@ -2,6 +2,9 @@
 // RUN: %{build} -fsycl-device-code-split=per_kernel -o %t.out
 // RUN: %{run} %t.out
 
+// https://github.com/intel/llvm/issues/15791
+// UNSUPPORTED: hip_amd
+
 #include "assignment.h"
 #include <iostream>
 using namespace sycl;

sycl/test-e2e/AtomicRef/exchange.cpp

@@ -1,6 +1,9 @@
 // RUN: %{build} -o %t.out
 // RUN: %{run} %t.out
 
+// https://github.com/intel/llvm/issues/15791
+// UNSUPPORTED: hip_amd
+
 #include "exchange.h"
 
 int main() { exchange_test_all<access::address_space::global_space>(); }