[llvm-branch-commits] CodeGen: Fix implementation of __builtin_trivially_relocate. (PR #140312)

[Peter Collingbourne via llvm-branch-commits]

https://github.com/pcc created https://github.com/llvm/llvm-project/pull/140312

The builtin is documented to copy `count` elements, but the implementation
copies `count` bytes. Fix that.