* exceptions.cc (RtlUnwind): Align declaration with MSDN.

* ntdll.h: Define CreateDisposition Flags.  Add comments.
	* winlean.h: Define FILE_SHARE_VALID_FLAGS if using Mingw64 headers.

winsup/cygwin/ntdll.h

@@ -24,6 +24,15 @@
 #define NtCurrentThread()  ((HANDLE) 0xfffffffe)
 
 /* CreateDisposition in NtCreateFile call. */
+#define FILE_SUPERSEDE			0x00000000
+#define FILE_OPEN			0x00000001
+#define FILE_CREATE			0x00000002
+#define FILE_OPEN_IF			0x00000003
+#define FILE_OVERWRITE			0x00000004
+#define FILE_OVERWRITE_IF		0x00000005
+#define FILE_MAXIMUM_DISPOSITION	0x00000005
+
+/* Creation information returned in IO_STATUS_BLOCK. */
 #define FILE_SUPERSEDED     0
 #define FILE_OPENED         1
 #define FILE_CREATED        2
@@ -31,6 +40,28 @@
 #define FILE_EXISTS         4
 #define FILE_DOES_NOT_EXIST 5
 
+/* CreateFile/OpenFile options */
+#define FILE_DIRECTORY_FILE		0x00000001
+#define FILE_WRITE_THROUGH		0x00000002
+#define FILE_SEQUENTIAL_ONLY		0x00000004
+#define FILE_NO_INTERMEDIATE_BUFFERING	0x00000008
+#define FILE_SYNCHRONOUS_IO_ALERT	0x00000010
+#define FILE_SYNCHRONOUS_IO_NONALERT	0x00000020
+#define FILE_NON_DIRECTORY_FILE		0x00000040
+#define FILE_CREATE_TREE_CONNECTION	0x00000080
+#define FILE_COMPLETE_IF_OPLOCKED	0x00000100
+#define FILE_NO_EA_KNOWLEDGE		0x00000200
+#define FILE_OPEN_FOR_RECOVERY		0x00000400
+#define FILE_RANDOM_ACCESS		0x00000800
+#define FILE_DELETE_ON_CLOSE		0x00001000
+#define FILE_OPEN_BY_FILE_ID		0x00002000
+#define FILE_OPEN_FOR_BACKUP_INTENT	0x00004000
+#define FILE_NO_COMPRESSION		0x00008000
+#define FILE_RESERVE_OPFILTER		0x00100000
+#define FILE_OPEN_REPARSE_POINT		0x00200000
+#define FILE_OPEN_NO_RECALL		0x00400000
+#define FILE_OPEN_FOR_FREE_SPACE_QUERY	0x00800000
+
 /* Relative file position values in NtWriteFile call. */
 #define FILE_WRITE_TO_END_OF_FILE      (-1LL)
 #define FILE_USE_FILE_POINTER_POSITION (-2LL)