[clang-format] [NFC] build clang-format with -Wall

When building clang-format with -Wall on Visual Studio 20119 we see the following, prevent this the only -Wall error
```
..FormatTokenLexer.cpp(45) : warning C4868: compiler may not enforce left-to-right evaluation order in braced initializer list
```
Reviewed By: HazardyKnusperkeks
Differential Revision: https://reviews.llvm.org/D113844