Update the vFile:open: description to note that the flags

in the packet are lldb enum values, not the open(2) oflags -- 
forgot about that wrinkle.  Also added a comment to File.h 
noting that the existing values cannot be modified or we'll
have a compatibilty break with any alternative platform
implementations, or older versions of lldb-server.

llvm-svn: 349282

lldb/docs/lldb-platform-packets.txt

@@ -303,7 +303,9 @@ for the lldb testsuite to be run on a remote target device/system.
 //
 //  request packet has the fields:
 //     1. ASCII hex encoded filename
-//     2. oflags to be passed to open(2), base 16
+//     2. flags passed to the open call, base 16.
+//        Note that these are not the oflags that open(2) takes, but
+//        are the constant values in enum OpenOptions from lldb's File.h
 //     3. mode bits, base 16
 //  
 //  response is F followed by the opened file descriptor in base 10.

lldb/include/lldb/Host/File.h

@@ -33,6 +33,8 @@ public:
   static int kInvalidDescriptor;
   static FILE *kInvalidStream;
 
+  // NB this enum is used in the lldb platform gdb-remote packet
+  // vFile:open: and existing values cannot be modified.
   enum OpenOptions {
     eOpenOptionRead = (1u << 0),  // Open file for reading
     eOpenOptionWrite = (1u << 1), // Open file for writing