Bug#913266: rustc fails to build many rust-* packages on arm64: LLVM ERROR: Only small and large code models are allowed on AArch64

[Adrian Bunk]

Package: rustc
Version: 1.30.0+dfsg1-2
Severity: serious

Example:

https://tests.reproducible-builds.org/debian/rb-pkg/unstable/arm64/rust-bytecount.html

...
   dh_auto_test -O--buildsystem=cargo
error: failed to run `rustc` to learn about target-specific information

Caused by:
  process didn't exit successfully: `rustc - --crate-name ___ --print=file-names --crate-type bin --crate-type rlib --crate-type dylib --crate-type cdylib --crate-type staticlib --crate-type proc-macro` (exit code: 1)
--- stderr
LLVM ERROR: Only small and large code models are allowed on AArch64

dh_auto_test: cargo build --verbose --verbose -j8 --target aarch64-unknown-linux-gnu -Zavoid-dev-deps returned exit code 101
make: *** [debian/rules:3: build] Error 25