_content/doc/articles/race_detector: document windows C compiler version requirements

Add a note documenting the requirement (as of Go 1.21) on Windows that
the installed C compiler support mingw-w64 version 8 or later, which
provides libsynchronization.a.

Fixes golang/go#61058.

Change-Id: I891d7d32df41387e1671a1ec9bac722c47a68ee5
Reviewed-on: https://go-review.googlesource.com/c/website/+/508461
Reviewed-by: Quim Muntal <[email protected]>
Reviewed-by: Cherry Mui <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Run-TryBot: Than McIntosh <[email protected]>

Author: thanm

_content/doc/articles/race_detector.html

@@ -422,6 +422,18 @@ <h2 id="Requirements">Requirements</h2>
   <code>darwin/arm64</code>, and <code>windows/amd64</code>.
 </p>
 
+<p>
+  On Windows, the race detector runtime is sensitive to the
+  version of the C compiler installed; as of Go 1.21, building
+  a program with <code>-race</code> requires a C compiler that
+  incorporates version 8 or later of the <code>mingw-w64</code>
+  runtime libraries. You can test your C compiler by invoking it
+  with the arguments
+  <code>--print-file-name libsynchronization.a</code>. A newer
+  compliant C compiler will print a full path for this library,
+  whereas older C compilers will just echo the argument.
+</p>
+
 <h2 id="Runtime_Overheads">Runtime Overhead</h2>
 
 <p>