Win32/Process.inc: [PR8527] Process::FileDescriptorIsDisplayed(fd) should not check by FILE_TYPE_CHAR. It must be better to check it with Console API.

The special file "NUL" is FILE_TYPE_CHAR with GetFileType(h). It was treated as display device and discarding output to NUL had failed. (eg. opt -o nul)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118678 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/System/Win32/Process.inc b/lib/System/Win32/Process.inc
index feb0806..15b41f0 100644
--- a/lib/System/Win32/Process.inc
+++ b/lib/System/Win32/Process.inc
@@ -132,7 +132,8 @@
 }
 
 bool Process::FileDescriptorIsDisplayed(int fd) {
-  return GetFileType((HANDLE)_get_osfhandle(fd)) == FILE_TYPE_CHAR;
+  DWORD Mode;	// Unused
+  return (GetConsoleMode((HANDLE)_get_osfhandle(fd), &Mode) != 0);
 }
 
 unsigned Process::StandardOutColumns() {