Add dist builder for Armv8-M Mainline

This commit adds the Armv8-M Mainline target in the list of targets that
get their dist components built. It also update the build-manifest so
that this target gets also its dist components uploaded.

Author: hug-dev

src/ci/docker/dist-various-1/Dockerfile

@@ -103,6 +103,7 @@ ENV TARGETS=$TARGETS,thumbv6m-none-eabi
 ENV TARGETS=$TARGETS,thumbv7m-none-eabi
 ENV TARGETS=$TARGETS,thumbv7em-none-eabi
 ENV TARGETS=$TARGETS,thumbv7em-none-eabihf
+ENV TARGETS=$TARGETS,thumbv8m.main-none-eabi
 ENV TARGETS=$TARGETS,riscv32imc-unknown-none-elf
 ENV TARGETS=$TARGETS,riscv32imac-unknown-none-elf
 ENV TARGETS=$TARGETS,armebv7r-none-eabi

src/tools/build-manifest/src/main.rs

@@ -98,6 +98,7 @@ static TARGETS: &'static [&'static str] = &[
     "thumbv7em-none-eabi",
     "thumbv7em-none-eabihf",
     "thumbv7m-none-eabi",
+    "thumbv8m.main-none-eabi",
     "wasm32-unknown-emscripten",
     "wasm32-unknown-unknown",
     "x86_64-apple-darwin",