[llvm] Do not use Console API if the output isn't a console device

This fixes the `-fcolor-diagnostics` to properly enable color output when not outputting to console devices, such as when using Ninja. This affects only Windows. Signed-off-by: Kacper Michajłow <kasper93@gmail.com>

Author: kasper93

llvm/lib/Support/raw_ostream.cpp

@@ -645,6 +645,11 @@ raw_fd_ostream::raw_fd_ostream(int fd, bool shouldClose, bool unbuffered,
  // Check if this is a console device. This is not equivalent to isatty.
  IsWindowsConsole =
  ::GetFileType((HANDLE)::_get_osfhandle(fd)) == FILE_TYPE_CHAR;
+
+ // If this isn't a console device, don't try to use the API to set the color.
+ // Switch to ANSI escape codes instead.
+ if (!IsWindowsConsole)
+ llvm::sys::Process::UseANSIEscapeCodes(true);
 #endif
 
  // Get the starting position.