Actually add the test

Author: RossBrunton

offload/unittests/OffloadAPI/device_code/localmem_static.c

@@ -0,0 +1,17 @@
+#include <gpuintrin.h>
+#include <stdint.h>
+
+[[clang::loader_uninitialized]]
+__gpu_local uint32_t shared_mem[64];
+
+__gpu_kernel void localmem_static(uint32_t *out) {
+  shared_mem[__gpu_thread_id(0)] = 2;
+
+  __gpu_sync_threads();
+
+  if (__gpu_thread_id(0) == 0) {
+    out[__gpu_block_id(0)] = 0;
+    for (uint32_t i = 0; i < __gpu_num_threads(0); i++)
+      out[__gpu_block_id(0)] += shared_mem[i];
+  }
+}