[bcl] Embed Source Link information (#12403)

Source Link allows IDEs/debuggers to retrieve a source file from a remote location like GitHub when the local file isn't available.

Specification: https://github.com/dotnet/designs/blob/e55c517a1e7f8dc35b092397058029531209d610/accepted/diagnostics/source-link.md

For now we only embed info about mono, cecil, corefx and corert since that covers 99% of what you usually want to debug and doesn't need fancy logic that reads git submodules and figures out their URLs.

Should enable use cases like https://twitter.com/jlaban/status/1084248087802060801

1 files changed, 3 insertions, 0 deletions

diff --git a/msvc/scripts/genproj.cs b/msvc/scripts/genproj.cs
index 2e1056d0bcb..ee1518a0b5d 100755
--- a/msvc/scripts/genproj.cs
+++ b/msvc/scripts/genproj.cs
@@ -713,6 +713,9 @@ public class MsbuildGenerator {
 
 		case "/features":
 			return true;
+
+		case "/sourcelink":
+			return true;
 		}
 
 		Console.Error.WriteLine ($"// Failing with : {arg}");