[RISC-V] Make mem* functions always available

[hvdijk]

Overview

[RISC-V] Make mem* functions always available

Reason for change

When we link in builtin functions, we attempted to detect when we need memcpy/memmove/memset to provide them when needed. This detection proved to not be entirely reliable: compiler passes run after linking in the builtin functions are permitted to insert additional references. When running SYCL-CTS, it turned out that function inlining can insert additional references to memcpy for the purpose of copying function arguments which, after inlining, no longer exist as separate function arguments.

Description of change

For non-RISC-V targets, we already unconditionally provide these functions in host::utils::getRelocations(), so it seems reasonable to just always provide them for RISC-V too.

Anything else we should know?

This also allows us to avoid some complexity in the definition of memmove that was only there to deal with the situation where memcpy might be unavailable. As that can no longer happen, that no longer needs to be taken into account.

Checklist

• Read and follow the project Code of Conduct.
• Make sure the project builds successfully with your changes.
• Run relevant testing locally to avoid regressions.
• Run clang-format-17 on all modified code.