[docs] Workaround old recommonmark version on buildbots

[rupprecht]

Summary

recommonmark 0.4.0 doesn't understand md -> rst links (and so adding .html is required), but recommonmark 0.5.0 emits a warning (which we treat as errors) when hitting this.

Work around this by temporarily using regular, non-markdown links.

Revert this after upgrading the buildbots to recommonmark 0.5.0, and then fix the links to not explicitly include the .html in these files (except llvm-addr2line, which is already broken on llvm.org).

[jhenderson]

html can be embedded in markdown? That was unexpected and sounds good. Does this work when generating man pages though instead of html?

[jhenderson]

In D63292#1543231, @jhenderson wrote:

html can be embedded in markdown? That was unexpected and sounds good. Does this work when generating man pages though instead of html?

If it doesn't solve the problem (because of man pages), maybe we're better off cutting our losses and changing the .md files to .rst, since the feedback on the mailing list seems to be that we can't upgrade the version of recommonmark.

[lebedev.ri]

In D63292#1551912, @jhenderson wrote:

In D63292#1543231, @jhenderson wrote:

html can be embedded in markdown? That was unexpected and sounds good. Does this work when generating man pages though instead of html?

If it doesn't solve the problem (because of man pages), maybe we're better off cutting our losses and changing the .md files to .rst, since the feedback on the mailing list seems to be that we can't upgrade the version of recommonmark.

*very* weak +1 here, it seems weird to use non-native .MD when sphinx is based on .RST.

[rupprecht]

Switching these docs to rst seems (unfortunately) better, abandoning this attempt.

[jhenderson]

In D63292#1554524, @rupprecht wrote:

Switching these docs to rst seems (unfortunately) better, abandoning this attempt.

Okay. I'll go ahead and fix things up over the next few days. I'm planning on expanding the majority of the docs anyway, so it's a good opportunity to switch over then.

llvm/docs/CommandGuide/llvm-addr2line.md

 # llvm-addr2line - a drop-in replacement for addr2line
 
 ## SYNOPSIS
 
 **llvm-addr2line** [*options*]
 
 ## DESCRIPTION
 
-**llvm-addr2line** is an alias for the [llvm-symbolizer](llvm-symbolizer) tool
-with different defaults. The goal is to make it a drop-in replacement for
-GNU's **addr2line**.
+**llvm-addr2line** is an alias for the
+<a href="llvm-symbolizer.html">llvm-symbolizer</a> tool with different defaults.
+The goal is to make it a drop-in replacement for GNU's **addr2line**.
 
 Here are some of those differences:
 
-* Defaults not to print function names. Use [-f](llvm-symbolizer-opt-f)
-  to enable that.
+* Defaults not to print function names. Use
+  <a href="llvm-symbolizer.html#llvm-symbolizer-opt-f">-f</a> to enable that.
 
-* Defaults not to demangle function names. Use [-C](llvm-symbolizer-opt-C)
-  to switch the demangling on.
-
-* Defaults not to print inlined frames. Use [-i](llvm-symbolizer-opt-i)
-  to show inlined frames for a source code location in an inlined function.
-
-* Uses [--output-style=GNU](llvm-symbolizer-opt-output-style) by default.
+* Defaults not to demangle function names. Use
+  <a href="llvm-symbolizer.html#llvm-symbolizer-opt-c">-C</a> to switch the
+  demangling on.
+
+* Defaults not to print inlined frames. Use
+  <a href="llvm-symbolizer.html#llvm-symbolizer-opt-i">-i</a> to show inlined
+  frames for a source code location in an inlined function.
+
+* Uses
+  <a href="llvm-symbolizer.html#llvm-symbolizer-opt-output-style">--output-style=GNU</a>
+  by default.
 
 ## SEE ALSO
 
-Refer to [llvm-symbolizer](llvm-symbolizer) for additional information.
+Refer to <a href="llvm-symbolizer.html">llvm-symbolizer</a> for additional information.

llvm/docs/CommandGuide/llvm-objcopy.md

 # llvm-objcopy - object copying tool
 
 ## SYNOPSIS
 
 **llvm-objcopy** [*options*]
 
 ## DESCRIPTION
 
 **llvm-objcopy** is a tool to copy and manipulate objects.
 
 The tool is still in active development, but in most scenarios it works as a
 drop-in replacement for GNU's **objcopy**.
 
 ## SEE ALSO
 
-[llvm-strip](llvm-strip.html)
+<a href="llvm-strip.html">llvm-strip</a>

llvm/docs/CommandGuide/llvm-ranlib.md

 # llvm-ranlib - generates an archive index
 
 ## SYNOPSIS
 
 **llvm-ranlib** [*options*]
 
 ## DESCRIPTION
 
-**llvm-ranlib** is an alias for the [llvm-ar](llvm-ar.html) tool that generates
-an index for an archive. It can be used as a replacement for GNU's **ranlib**
-tool.
+**llvm-ranlib** is an alias for the <a href="llvm-ar.html">llvm-ar</a> tool
+that generates an index for an archive. It can be used as a replacement for
+GNU's **ranlib** tool.
 
 Running **llvm-ranlib** is equivalent to running **llvm-ar s**.
 
 ## SEE ALSO
 
-Refer to [llvm-ar](llvm-ar.html) for additional information.
+Refer to <a href="llvm-ar.html">llvm-ar</a> for additional information.

llvm/docs/CommandGuide/llvm-readelf.md

 # llvm-readelf - a drop-in replacement for readelf
 
 ## SYNOPSIS
 
 **llvm-readelf** [*options*]
 
 ## DESCRIPTION
 
-**llvm-readelf** is an alias for the [llvm-readobj](llvm-readobj.html) tool with
-a command-line interface and output style more closely resembling GNU
-**readelf**.
+**llvm-readelf** is an alias for the
+<a href="llvm-readobj.html">llvm-readobj</a> tool with a command-line interface
+and output style more closely resembling GNU **readelf**.
 
 Here are some of those differences:
 
 * Uses `--elf-output-style=GNU` by default.
 
 * Allows single-letter grouped flags (e.g. `llvm-readelf -SW` is the same as
   `llvm-readelf -S -W`).
 
 * Allows use of `-s` as an alias for `--symbols` (versus `--section-headers` in
   **llvm-readobj**) for GNU **readelf** compatibility.
 
 * Prevents use of `-sr`, `-sd`, `-st` and `-dt` **llvm-readobj** aliases, to
   avoid conflicting with standard GNU **readelf** grouped flags.
 
 ## SEE ALSO
 
-Refer to [llvm-readobj](llvm-readobj.html) for additional information.
+Refer to <a href="llvm-readobj.html">llvm-readobj</a> for additional information.

llvm/docs/CommandGuide/llvm-strip.md

 # llvm-strip - object stripping tool
 
 ## SYNOPSIS
 
 **llvm-strip** [*options*]
 
 ## DESCRIPTION
 
 **llvm-strip** is a tool to strip sections and symbols from object files.
 
 The tool is still in active development, but in most scenarios it works as a
 drop-in replacement for GNU's **strip**.
 
 ## SEE ALSO
 
-[llvm-objcopy](llvm-objcopy.html)
+<a href="llvm-objcopy.html">llvm-objcopy</a>