Revert "[SYCL] temporarily disable tests" (intel#1149)

Revert "temporarily turning off three tests that seem to fail only on CI system. Investigating this is a priority, but we need to disable tests to reduce false negative flags in other PRs. (intel#983)"

This reverts commit d81e41a.

Author: Pavel Chupin

SYCL/Basic/context-with-multiple-devices.cpp

@@ -1,6 +1,3 @@
-// UNSUPPORTED: windows || linux
-//   temporarily disabled
-
 // REQUIRES: accelerator, opencl-aot
 
 // RUN: %clangxx -fsycl -fintelfpga -fsycl-unnamed-lambda %s -o %t2.out

SYCL/Basic/interop/check_carrying_real_kernel_IDs.cpp

@@ -1,6 +1,3 @@
-// UNSUPPORTED: windows || linux
-//   temporarily disabled
-
 // REQUIRES: opencl, opencl_icd
 // RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out %opencl_lib
 // RUN: %ACC_RUN_PLACEHOLDER %t.out

SYCL/DiscardEvents/invalid_event_exceptions.cpp

@@ -1,6 +1,3 @@
-// UNSUPPORTED: windows || linux
-//   temporarily disabled
-
 // RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
 //
 // RUN: %HOST_RUN_PLACEHOLDER %t.out