fdsink,fdsrc: Add support for MinGW build and fix to avoid unexpected CRLF sequence
fdsrc,fdsink: Set binary mode on FD
Default mode of STD handles on Windows is text mode, and OS will
insert CRLF sequence by default.
Co-authored-by: Seungha Yang <seungha@centricular.com>
coreelements: Use G_OS_WIN32 macro
* HAVE_WIN32 is not defined elsewhere
* Enables fdsrc/fdsink for MinGW build as well
Co-authored-by: Seungha Yang <seungha@centricular.com>