[LLD][ELF] Add lld --time-trace to man page and release notes

[russell.gallop]

Summary

Follow on from: https://reviews.llvm.org/D71060

This adds the new options to the lld man page and release notes.

[ruiu]

LGTM

[MaskRay]

lld/docs/ReleaseNotes.rst

27

--time-trace

Also, the feature was added in the last release. It is not correct to mention it for LLD 11.

[russell.gallop]

Change to double dashes.

Note that there are a few places in the the man page that will also need to be updated (e.g. --thinlto-*).

[russell.gallop]

lld/docs/ReleaseNotes.rst

27

--time-trace

Thanks for pointing that out.

Also, the feature was added in the last release. It is not correct to mention it for LLD 11.

That would be a surprise to me. I can't see an equivalent of e7cb374433095219069ef767f70c0c9159a65b7c in release/10.x.

Please can you let me know why you think that this was in the last release?

Thanks

[MaskRay]

lld/docs/ReleaseNotes.rst

27

I somehow thought --time-trace was included in release/10.x. It turns out it is not. Adding it for 11 release notes seem good.

lld/docs/ld.lld.1

535

-- to -

Fl carries a dash by itself.

You can read the man page with man docs/ld.lld.1

[russell.gallop]

Removed excess dashes in man page. Checked with:

man -l ld.lld.1

[MaskRay]

Thanks!

lld/docs/ReleaseNotes.rst

 from the `LLVM releases web site <https://llvm.org/releases/>`_.
 
 Non-comprehensive list of changes in this release
 =================================================
 
 ELF Improvements
 ----------------
 
+* New ``--time-trace`` option records a time trace file that can be viewed in
+  chrome://tracing. The file can be specified with ``--time-trace-file``.
+  Trace granularity can be specified with ``--time-trace-granularity``.
+  (`D71060 <https://reviews.llvm.org/D71060>`_)
 * ...
 
 Breaking changes
 ----------------
 
 * One-dash form of some long option (``--thinlto-*``, ``--lto-*``, ``--shuffle-sections=``)
   are no longer supported.
 

lld/docs/ld.lld.1

 .It Fl -thinlto-jobs Ns = Ns Ar value
 Number of ThinLTO jobs.
 .It Fl -threads Ns = Ns Ar N
 Number of threads.
 .Cm all
 (default) means all of concurrent threads supported.
 .Cm 1
 disables multi-threading.
+.It Fl -time-trace
+Record time trace.
+.It Fl -time-trace-file Ns = Ns Ar file
+Write time trace output to
+.Ar file .
+.It Fl -time-trace-granularity Ns = Ns Ar value
+Minimum time granularity (in microseconds) traced by time profiler.
 .It Fl -trace
 Print the names of the input files.
 .It Fl -trace-symbol Ns = Ns Ar symbol , Fl y Ar symbol
 Trace references to
 .Ar symbol .
 .It Fl -undefined Ns = Ns Ar symbol , Fl u Ar symbol
 If
 .Ar symbol