[UR][CUDA][HIP] Fix UR_PROGRAM_BUILD_INFO_LOG query (#18678)

This query was using `strnlen` on an uninitialized char array so it may
return an incorrect length for the build log.

This occasionally resulted in uninitialized data being printed to the
user.

Author: npmiller

unified-runtime/source/adapters/cuda/program.hpp

@@ -53,6 +53,10 @@ struct ur_program_handle_t_ : ur::cuda::handle_base {
         KernelReqdWorkGroupSizeMD{}, KernelMaxWorkGroupSizeMD{},
         KernelMaxLinearWorkGroupSizeMD{}, KernelReqdSubGroupSizeMD{} {
     urContextRetain(Context);
+
+    // When the log is queried we use strnlen(InfoLog), so it needs to be
+    // initialized like this when it's empty to correctly return 0.
+    InfoLog[0] = '\0';
   }
 
   ~ur_program_handle_t_() { urContextRelease(Context); }

unified-runtime/source/adapters/hip/program.hpp

@@ -52,6 +52,10 @@ struct ur_program_handle_t_ : ur::hip::handle_base {
         RefCount{1}, Context{Ctxt}, Device{Device}, KernelReqdWorkGroupSizeMD{},
         KernelReqdSubGroupSizeMD{} {
     urContextRetain(Context);
+
+    // When the log is queried we use strnlen(InfoLog), so it needs to be
+    // initialized like this when it's empty to correctly return 0.
+    InfoLog[0] = '\0';
   }
 
   ~ur_program_handle_t_() { urContextRelease(Context); }

unified-runtime/test/conformance/program/urProgramGetBuildInfo.cpp

@@ -55,8 +55,6 @@ TEST_P(urProgramGetBuildInfoTest, SuccessOptions) {
 }
 
 TEST_P(urProgramGetBuildInfoTest, SuccessLog) {
-  UUR_KNOWN_FAILURE_ON(uur::CUDA{});
-
   size_t property_size = 0;
   const ur_program_build_info_t property_name = UR_PROGRAM_BUILD_INFO_LOG;