[SYCL] Re-enable SYCL/Reduction/ tests (intel#1153)

reduction_nd_lambda.cpp was supposed to be re-enabled together with
intel#1134.

For reduction_big_data.cpp the logs with failure expired, not sure how
to deal with it. I did very brief local run of it which passed. As such,
re-enable and deal with it when/if it fails to gather some input data.

Author: aelovikov-intel

SYCL/Reduction/reduction_big_data.cpp

@@ -1,5 +1,3 @@
-// REQUIRES: TEMPORARILY_DISABLED
-// Temporarily disabled due to flaky unrelated failures
 // RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
 // RUN: %GPU_RUN_PLACEHOLDER %t.out
 // RUN: %ACC_RUN_PLACEHOLDER %t.out

SYCL/Reduction/reduction_nd_lambda.cpp

@@ -1,5 +1,3 @@
-// Test disabled due to sporadic failure
-// REQUIRES: TEMPORARILY_DISABLED
 // RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
 // RUNx: %HOST_RUN_PLACEHOLDER %t.out
 // RUN: %CPU_RUN_PLACEHOLDER %t.out