Use Linux-built cache/sysroot for Mac CI tester (#18086)

This PR makes the CircleCI builders use the sysroot built by the Linux builder on the mac bot, instead of having the mac bot rebuild all the libraries. It does this by attaching the same workspace that the linux testers do, and then removing the Linux-specific binaries and emsdk, and using the mac EMSDK instead.

Author: dschuff

.circleci/config.yml

@@ -97,19 +97,19 @@ commands:
             echo "WASM_ENGINES = []" >> .emscripten
             test -f ~/vms/wasmtime && echo "WASMTIME = os.path.expanduser(os.path.join('~', 'vms', 'wasmtime')) ; WASM_ENGINES.append(WASMTIME)" >> .emscripten || true
             test -f ~/vms/wasmer && echo "WASMER = os.path.expanduser(os.path.join('~', 'vms', 'wasmer')) ; WASM_ENGINES.append(WASMER)" >> .emscripten || true
-            test -d ~/wasi-sdk && cp -ar ~/wasi-sdk/lib/ ~/emsdk/upstream/lib/clang/16.0.0/
+            test -d ~/wasi-sdk && cp -a ~/wasi-sdk/lib/ ~/emsdk/upstream/lib/clang/16.0.0/
             cd -
             echo "final .emscripten:"
             cat ~/emsdk/.emscripten
       - emsdk-env
       - npm-install
+  build-libs:
+    description: "Build all libraries"
+    steps:
       - run:
           name: clear cache
           command: |
             ./emcc --clear-cache
-  build-libs:
-    description: "Build all libraries, and freeze the cache"
-    steps:
       - pip-install
       - run:
           name: embuilder build ALL
@@ -584,6 +584,7 @@ jobs:
     executor: mac
     environment:
       EMTEST_SKIP_V8: "1"
+      EMCC_SKIP_SANITY_CHECK: "1"
     steps:
       - run:
           name: Install brew package dependencies
@@ -594,7 +595,13 @@ jobs:
             brew list ninja || brew install ninja
             brew list python3 || brew install python3
             brew list pkg-config || brew install pkg-config
+      - attach_workspace:
+          at: ~/
       - checkout
+      - run:
+          name: Remove Linux binaries
+          command: |
+            rm -rf ~/emsdk ~/vms
       - build
       # note we do *not* build all libraries and freeze the cache; as we run
       # only limited tests here, it's more efficient to build on demand
@@ -655,4 +662,9 @@ workflows:
             - build-linux
       - test-latest-node
       - test-windows
-      - test-mac
+      - test-mac:
+          # The mac tester also uses the libraries built on the linux builder to
+          # save total build time (this is fine because the libraries are wasm
+          # and do not depend on the underlying build platform)
+          requires:
+            - build-linux