flags for Windows

[sabudilovskiy]

This check breaks my build under Windows, because I use clang (in msvc compatibility mode).

fast_float/CMakeLists.txt

Line 59 in d28a332

target_compile_options(fast_float INTERFACE /permissive-)

[lemire]

@sabudilovskiy We run tests in CI with ClangCL:

https://github.com/fastfloat/fast_float/blob/main/.github/workflows/vs17-clang-ci.yml

Please provide reproducible commands to verify the issue you are reporting.