Add some basic testing of arm64 linux (#1247)

test/test.sh

@@ -1,21 +1,29 @@
 #!/usr/bin/env bash
 
 echo "test the standard workflow (as close as possible to how a user would do it, in the shell)"
+echo "machine: $(uname -m)"
+echo "kernel: $(uname -s)"
 
 set -x
 set -e
 
 # Test that arbitrary (non-released) versions can be installed and
 # activated.
-./emsdk install sdk-upstream-1b7f7bc6002a3ca73647f41fc10e1fac7f06f804
-./emsdk activate sdk-upstream-1b7f7bc6002a3ca73647f41fc10e1fac7f06f804
-source ./emsdk_env.sh
-which emcc
-emcc -v
+# This test cannot run on linux-arm64 because only certain binaries
+# get uploaded for this architecture.
+if [[ !($(uname -s) == "Linux" && $(uname -m) == "aarch64") ]]; then
+  ./emsdk install sdk-upstream-1b7f7bc6002a3ca73647f41fc10e1fac7f06f804
+  ./emsdk activate sdk-upstream-1b7f7bc6002a3ca73647f41fc10e1fac7f06f804
+  source ./emsdk_env.sh
+  which emcc
+  emcc -v
+fi
 
+# Install an older version of the SDK that requires EM_CACHE to be
+# set in the environment, so that we can test it is later removed
+# This test only runs on x64 because we didn't build arm binaries
+# when this older version of the SDK was built.
 if [[ $(uname -m) == "x86_64" ]]; then
-  # Install an older version of the SDK that requires EM_CACHE to be
-  # set in the environment, so that we can test it is later removed
   ./emsdk install sdk-1.39.15
   ./emsdk activate sdk-1.39.15
   source ./emsdk_env.sh