[docs][llvm-dwarfdump] Make some option descriptions clearer and more precise

[jhenderson]

Summary

Some of the wording in the doc (taken largely from the help text), was a little imprecise in some cases, so this patch makes it a little more precise.

[JDevlieghere]

Thanks James! LGTM

[probinson]

docs/CommandGuide/llvm-dwarfdump.rst

71

This also applies to regex, according to the help text for regex?

105–106

Maybe "only show children to..." ?

Just for my curiosity, does this also limit the depth displayed when you dump an entire .debug_info/types section?

[jhenderson]

docs/CommandGuide/llvm-dwarfdump.rst

71

I don't think we need to duplicate the references. The interaction is described in the --regex description below, which itself also only applies to --option name, so anything we say here is redundant.

105–106

I think the "only show children" bit is important, since the initial root doesn't count as 1 (i.e. -r 0 prints the root tag, and no children, -r 1 prints the first-level children etc).

The switch does apply to .debug_info/types dumping, not just when displaying specific entries.

[jhenderson]

Improve --recurse-depth text.

[probinson]

LGTM

docs/CommandGuide/llvm-dwarfdump.rst

 
 .. option:: --help-list
 
             Show help and usage for this command without grouping the options
             into categories.
 
 .. option:: -i, --ignore-case
 
-            Ignore case distinctions when searching.
+            Ignore case distinctions when using :option:`--name`.
 
-.. option:: -n <pattern>, --name=<pattern>
+.. option:: -n <name>, --name=<name>
 
             Find and print all debug info entries whose name
-            (`DW_AT_name` attribute) matches the exact text in
-            <pattern>. Use the :option:`--regex` option to have
-            <pattern> become a regular expression for more flexible
-            pattern matching.
+            (`DW_AT_name` attribute) is <name>.
 
 .. option:: --lookup=<address>
 
             Lookup <address> in the debug information and print out the file,
             function, block, and line table details.
 
 .. option:: -o <path>
 
             Redirect output to a file specified by <path>, where `-` is the
             standard output stream.
 
 .. option:: -p, --show-parents
 
             Show a debug info entry's parents when selectively printing with
             the `=<offset>` argument of :option:`--debug-info`, or options such
             as :option:`--find` or :option:`--name`.
 
 .. option:: --parent-recurse-depth=<N>
 
-            Only recurse to a maximum depth of <N> when displaying parents of
-            debug info entries.
+            When displaying debug info entry parents, only show them to a
+            maximum depth of <N>.
 
 .. option:: --quiet
 
             Use with :option:`--verify` to not emit to `STDOUT`.
 
 .. option:: -r <N>, --recurse-depth=<N>
 
-            Only recurse to a maximum depth of <N> when dumping debug info
-            entries.
+            When displaying debug info entries, only show children to a maximum
+            depth of <N>.
 
 .. option:: --statistics
 
             Collect debug info quality metrics and print the results
             as machine-readable single-line JSON output.
 
 .. option:: --summarize-types
 
             Abbreviate the description of type unit entries.
 
 .. option:: -x, --regex
 
-            Treat any <pattern> strings as regular expressions when searching
-            instead of just as an exact string match.
+            Treat any <name> strings as regular expressions when searching
+            with :option:`--name`. If :option:`--ignore-case` is also specified,
+            the regular expression becomes case-insensitive.
 
 .. option:: -u, --uuid
 
             Show the UUID for each architecture.
 
 .. option:: --diff
 
             Dump the output in a format that is more friendly for comparing