Initial take on CI for emscripten.

This uses GitHub actions and installs the Emscripten SDK's
latest version and activates it. At some point, this should
probably change to a fixed version that is periodically
incremented once some baseline support level is determined.

This is just compiling and running what's needed for `amsss`
for now until other pieces are in place for building and
running more of everything.

Author: waywardmonkeys

.github/workflows/build-and-test.yml

@@ -66,6 +66,35 @@ jobs:
          nmake /f w3i6mv.nmk all testci testansi testpollnone
       shell: cmd
 
+  emscripten:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: emsdk
+      run: |
+        git clone https://github.com/emscripten-core/emsdk.git
+        cd emsdk
+        ./emsdk install latest
+        ./emsdk activate latest
+    - name: build via emscripten
+      run: |
+        source emsdk/emsdk_env.sh
+        mkdir build
+        cd build
+        emcc -I../code -o mps.o -c ../code/mps.c
+        emcc -Icode -o testlib.o -c code/testlib.c
+        emcc -Icode -o fmtdy.o -c code/fmtdy.c
+        emcc -Icode -o fmtdytst.o -c code/fmtdytst.c
+        emcc -Icode -o amsss.o -c code/amsss.c
+        emcc -o amsss amsss.o mps.o testlib.o fmtdy.o fmtdytst.o
+    - name: test via node
+      run: |
+        source emsdk/emsdk_env.sh
+        cd build
+        node ./amsss
+
 
 # A. REFERENCES
 #

design/tests.txt

@@ -311,6 +311,9 @@ least::
 
 as defined by the `.ci.github.config`_.
 
+_`.ci.run.emscripten`: On Windows, the CI services run commands to install
+the Emscripten SDK and then perform some basic builds with it.
+
 _`.ci.run.other.targets`: On some platforms we arrange to run the testansi,
 testpollnone, testratio, and testscheme targets.  [Need to explain
 why, where, etc.  RB 2023-01-15]