update llvm-dis header with available options

llvm/tools/llvm-dis/llvm-dis.cpp

@@ -11,7 +11,23 @@
 //  llvm-dis [options] x.bc - Read LLVM bitcode from the x.bc file, write asm
 //                            to the x.ll file.
 //  Options:
-//      --help   - Output information about command line switches
+//
+//  Color Options:
+//      --color                 - Use colors in output (default=autodetect)
+//
+//  Disassembler Options:
+//      -f                      - Enable binary output on terminals
+//      --materialize-metadata  - Load module without materializing metadata,
+//                                then materialize only the metadata
+//      -o <filename>           - Override output filename
+//      --show-annotations      - Add informational comments to the .ll file
+//
+//  Generic Options:
+//      --help                  - Display available options
+//                                (--help-hidden for more)
+//      --help-list             - Display list of available options
+//                                (--help-list-hidden for more)
+//      --version               - Display the version of this program
 //
 //===----------------------------------------------------------------------===//