lang/rust-nightly: Update to 1.44.0.20200417
- Add workaround to fix build when CC/CXX have "clang" in them [1]
- Add patch to allow build with outdated libgit2 0.99.0
Changes: https://github.com/rust-lang/rust/compare/485c5fb6e1...7f3df57724
PR: 238556 [1]