Add documentation for llvm-dwarfdump tool

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209173 91177308-0d34-0410-b5e6-96231b3b80d8

docs/CommandGuide/index.rst

@@ -28,6 +28,7 @@ Basic Commands
    llvm-profdata
    llvm-stress
    llvm-symbolizer
+   llvm-dwarfdump
 
 Debugging Tools
 ~~~~~~~~~~~~~~~

docs/CommandGuide/llvm-dwarfdump.rst

@@ -0,0 +1,30 @@
+llvm-dwarfdump - print contents of DWARF sections
+=================================================
+
+SYNOPSIS
+--------
+
+:program:`llvm-dwarfdump` [*options*] [*filenames...*]
+
+DESCRIPTION
+-----------
+
+:program:`llvm-dwarfdump` parses DWARF sections in the object files
+and prints their contents in human-readable form.
+
+OPTIONS
+-------
+
+.. option:: -debug-dump=section
+
+  Specify the DWARF section to dump.
+  For example, use ``abbrev`` to dump the contents of ``.debug_abbrev`` section,
+  ``loc.dwo`` to dump the contents of ``.debug_loc.dwo`` etc.
+  See ``llvm-dwarfdump --help`` for the complete list of supported sections.
+  Use ``all`` to dump all DWARF sections. It is the default.
+
+EXIT STATUS
+-----------
+
+:program:`llvm-dwarfdump` returns 0. Other exit codes imply internal
+program error.