[llvm] [libsycl] add USM alloc/free functions (PR #184111)

[Sergey Semenov via llvm-commits]

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@@ -102,6 +103,13 @@ ol_device_type_t convertDeviceTypeToOL(info::device_type DeviceType);
 /// \returns SYCL device type matching specified liboffload device type.
 info::device_type convertDeviceTypeToSYCL(ol_device_type_t DeviceType);
 
+/// Converts SYCL USM  type to liboffload type.
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sergey-semenov wrote:

```suggestion
/// Converts a SYCL USM type to a liboffload type.
```

https://github.com/llvm/llvm-project/pull/184111