[SYCL] Disable cassert fallback SPV loading (#6176)

Currently, sycl-post-link tool will analyze user's device image and record which device libraries are actually required by user, sycl runtime will read the info and load the required fallback spv file. However, old compiler would always mark "cassert" fallback spv as required, this was to bypass a FE issue. So, if anyone uses old compiler + new SYCL runtime with online link enabled, unnecessary cassert fallback spv loading will be observed. This PR will ignore "cassert" fallback spv in sycl runtime, ignoring it is OK for now since "cassert" fallback has not been fully implemented.

This PR depends on #6167

Signed-off-by: jinge90 <[email protected]>

Author: jinge90

sycl/source/detail/program_manager/program_manager.cpp

@@ -992,6 +992,16 @@ ProgramManager::build(ProgramPtr Program, const ContextImplPtr Context,
               << ")\n";
   }
 
+  // TODO: old sycl compiler always marks cassert fallback device library as
+  // "required", this will lead to compatibilty issue when we enable online
+  // link in SYCL runtime. If users compile their code with old compiler and run
+  // their executable with latest SYCL runtime, cassert fallback spv file will
+  // always be loaded which is not expected, cassert device library development
+  // is still in progress, the unexpected loading may lead to runtime problem.
+  // So, we clear bit 0 in device library require mask to avoid loading cassert
+  // fallback device library and will revert this when cassert development is
+  // done.
+  DeviceLibReqMask &= 0xFFFFFFFE;
   bool LinkDeviceLibs = (DeviceLibReqMask != 0);
 
   // TODO: this is a temporary workaround for GPU tests for ESIMD compiler.