Add update-dmd-rewrite.sh script

[kinke]

See #4245.

[kinke]

For local testing, assuming you are in the parent dir of the ldc clone:

$ cp -R ldc ldc-mono-vanilla
$ INITIALIZE=1 ldc/tools/update-dmd-rewrite.sh

The ldc-mono dir then contains a lot of new tags (incl. dmd-rewrite-first-merged-dmd-druntime-with-ldc-druntime-patches) and the dmd-rewrite-{master,stable} branches. [Rewritten dmd.tmp is temporarily kept.]

To simulate an update, re-run without INITIALIZE=1 and with commented-out rm -rf ../ldc-mono && cp -R ../ldc-mono-vanilla ../ldc-mono line.

[JohanEngelen]

For local testing, assuming you are in the parent dir of the ldc clone:

$ cp -R ldc ldc-mono-vanilla
$ INITIALIZE=1 ldc/tools/update-dmd-rewrite.sh

The ldc-mono dir then contains a lot of new tags (incl. dmd-rewrite-first-merged-dmd-druntime-with-ldc-druntime-patches) and the dmd-rewrite-{master,stable} branches. [Rewritten dmd.tmp is temporarily kept.]

To simulate an update, re-run without INITIALIZE=1 and with commented-out rm -rf ../ldc-mono && cp -R ../ldc-mono-vanilla ../ldc-mono line.

Can you add all this info to the script file?

[kinke]

It should now be safe to execute the script for local testing (edit: discard the previous instructions above, just run tools/update-dmd-rewrite.sh). DMD master has gotten new commits since the initial rewrite, so when executing the script now, it should update the dmd-rewrite-master branch. If you just want to check without actual pushing, use git push --dry-run … in line 101:

…
+ git push --dry-run --tags ldc dmd-rewrite-master dmd-rewrite-stable
To github.com:ldc-developers/ldc.git
   ab0d4ab2e..9b3ea5028  dmd-rewrite-master -> dmd-rewrite-master
…