[clang-tools-extra] Fix 'newline in constant' encoding issue in clangd sources (PR #78085)

[kadir çetinkaya via cfe-commits]

kadircet wrote:

I am not sure if this is a viable solution in the long term as LLVM don't really use BOMs in the sources (a quick scan shows only 4 files with BOMs), hence these changes can easily be overridden without someone noticing.

Any reason you can't configure MSVC to treat all of the LLVM sources as UTF8 ?

https://github.com/llvm/llvm-project/pull/78085