Add no_std checks

Author: aumetra

.circleci/config.yml

@@ -288,6 +288,9 @@ jobs:
       - restore_cache:
           keys:
             - cargocache-v2-package_core-rust:1.73-{{ checksum "Cargo.lock" }}
+      - run:
+          name: Add thumbv7em-none-eabi target
+          command: rusup target add thumbv7em-none-eabi && rustup target list --installed
       - run:
           name: Add wasm32 target
           command: rustup target add wasm32-unknown-unknown && rustup target list --installed
@@ -299,6 +302,10 @@ jobs:
           name: Build library for wasm target (no features)
           working_directory: ~/project/packages/core
           command: cargo wasm --locked --no-default-features
+      - run:
+          name: Build library for no_std target (no features)
+          working_directory: ~/project/packages/core
+          command: cargo no-std --locked --no-default-features
       - run:
           name: Run unit tests (no features)
           working_directory: ~/project/packages/core

packages/core/.cargo/config

@@ -1,4 +1,5 @@
 [alias]
+no-std = "build --release --lib --target thumbv7em-none-eabi"
 wasm = "build --release --lib --target wasm32-unknown-unknown"
 wasm-debug = "build --lib --target wasm32-unknown-unknown"
 unit-test = "test --lib"