Re-support hwasan. Replace /dev/null with -

Since the error on hwasan was able to be reproduced locally and the "underlying" (though still not fully understood) issue was discovered, this commit re-adds support for running the test under hwasan and replaces the problematic llc output argument that was causing the test to fail under hwasan.

Author: Icohedron

llvm/test/CodeGen/SPIRV/opencl/reflect-error.ll

@@ -1,6 +1,5 @@
-; RUN: not llc -verify-machineinstrs -O0 -mtriple=spirv64-unknown-unknown %s -o /dev/null 2>&1 | FileCheck %s
-; RUN: not llc -verify-machineinstrs -O0 -mtriple=spirv32-unknown-unknown %s -o /dev/null 2>&1 | FileCheck %s
-; UNSUPPORTED: hwasan
+; RUN: not llc -verify-machineinstrs -O0 -mtriple=spirv64-unknown-unknown %s -o - 2>&1 | FileCheck %s
+; RUN: not llc -verify-machineinstrs -O0 -mtriple=spirv32-unknown-unknown %s -o - 2>&1 | FileCheck %s
 
 ; CHECK: LLVM ERROR: %{{.*}} = G_INTRINSIC intrinsic(@llvm.spv.reflect), %{{.*}}, %{{.*}} is only supported with the GLSL extended instruction set.