Has the arm branch already been moved to git?
GNU C/C++ Compiler
You can find the sources to Arm Embedded GCC under svn://gcc.gnu.org/svn/gcc/branches/ARM/. All contributions are made to trunk and patches are cherry-picked on a need basis to the Arm embedded branches.
Yes it has, see https://gcc.gnu.org/git.html and look for vendor branches.
You are probably looking for remotes/origin/vendors/ARM/heads/arm-9-branch. Note that vendor branches are not pulled in by default so you have to configure get to pull them with something like:
git config --add remote.origin.fetch "+refs/vendors/ARM/heads/arm-9-branch:refs/vendors/ARM/heads/arm-9-branch"
View all questions in Arm Compilers forum