Enable -Zrandomize-layout on nightly toolchain

Author: dtolnay

action.yml

@@ -106,5 +106,12 @@ runs:
         fi
       shell: bash
 
+    - run: |
+        : enable randomized type layout
+        if rustc +${{steps.parse.outputs.toolchain}} --version --verbose | grep -q '^release: .*nightly'; then
+          echo RUSTFLAGS="-Zrandomize-layout ${RUSTFLAGS}" >> $GITHUB_ENV
+        fi
+      shell: bash
+
     - run: rustc +${{steps.parse.outputs.toolchain}} --version --verbose
       shell: bash