[SYCL][HIP] Fix max constant memory device query (#5168)

This fixes the `Basic/info.cpp` test for HIP AMD.

The issue here is that AMD GPU report a very large constant memory
(confirmed using `clinfo` as well). But the HIP entry point to query
that information takes a `int*`. So the value will show up as negative,
even though it's the correct value.

So remove the assertion on if the value is positive and cast it back to
`unsigned` before returning it.

Author: npmiller

sycl/plugins/hip/pi_hip.cpp

@@ -1319,12 +1319,16 @@ pi_result hip_piDeviceGetInfo(pi_device device, pi_device_info param_name,
                    pi_uint64{bytes});
   }
   case PI_DEVICE_INFO_MAX_CONSTANT_BUFFER_SIZE: {
-    int constant_memory = 0;
+    unsigned int constant_memory = 0;
+
+    // hipDeviceGetAttribute takes a int*, however the size of the constant
+    // memory on AMD GPU may be larger than what can fit in the positive part
+    // of a signed integer, so use an unsigned integer and cast the pointer to
+    // int*.
     cl::sycl::detail::pi::assertion(
-        hipDeviceGetAttribute(&constant_memory,
+        hipDeviceGetAttribute(reinterpret_cast<int *>(&constant_memory),
                               hipDeviceAttributeTotalConstantMemory,
                               device->get()) == hipSuccess);
-    cl::sycl::detail::pi::assertion(constant_memory >= 0);
 
     return getInfo(param_value_size, param_value, param_value_size_ret,
                    pi_uint64(constant_memory));