[NAVI3X] [MI308X] Fix UT hangs and failures for ROCm RCCL builds (#2124)

* Update toolchain with compiler flags for RelWithDebInfo

[ROCm/rccl commit: e905d52fc0]

projects/rccl/toolchain-linux.cmake

@@ -15,6 +15,7 @@ endif()
 if (NOT DEFINED ENV{CXXFLAGS})
   set(CMAKE_CXX_FLAGS_DEBUG "-g -O1")
   set(CMAKE_CXX_FLAGS_RELEASE "-O3")
+  set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O3 -g")
 endif()
 
 if (NOT DEFINED ENV{CC})
@@ -26,4 +27,5 @@ endif()
 if (NOT DEFINED ENV{CFLAGS})
   set(CMAKE_C_FLAGS_DEBUG "-g -O1")
   set(CMAKE_C_FLAGS_RELEASE "-O3")
+  set(CMAKE_C_FLAGS_RELWITHDEBINFO "-O3 -g")
 endif()