CI: Adjust stage Test Assertions w/ Parallel Callbacks

Add build without assertions to ensure the code actually compiles without error,
and disable the stage entirely for LFortran, which is currently unable
to correctly compile this code (issue #68)

Author: bonachea

.github/workflows/build.yml

@@ -188,10 +188,12 @@ jobs:
         ( set +e ; fpm run  --example invoke-via-macro  ${FPM_FLAGS} --flag "$FFLAGS" ; test $? = $ERROR_STOP_CODE )
 
     - name: Test Assertions w/ Parallel Callbacks
+      if: ${{ matrix.compiler != 'lfortran' }} # issue #68
       env:
-        FPM_FLAGS: ${{ env.FPM_FLAGS }} --flag -DASSERTIONS --flag -DASSERT_MULTI_IMAGE --flag -DASSERT_PARALLEL_CALLBACKS
+        FPM_FLAGS: ${{ env.FPM_FLAGS }} --flag -DASSERT_MULTI_IMAGE --flag -DASSERT_PARALLEL_CALLBACKS
       run: |
         set -x
-        ( set +e ; fpm run  --example false-assertion   ${FPM_FLAGS} --flag "$FFLAGS" ; test $? = $ERROR_STOP_CODE )
-        ( set +e ; fpm run  --example simple-assertions ${FPM_FLAGS} --flag "$FFLAGS" ; test $? = $ERROR_STOP_CODE )
-        ( set +e ; fpm run  --example invoke-via-macro  ${FPM_FLAGS} --flag "$FFLAGS" ; test $? = $ERROR_STOP_CODE )
+        fpm run  --example false-assertion   ${FPM_FLAGS} --flag "$FFLAGS"
+        fpm run  --example invoke-via-macro  ${FPM_FLAGS} --flag "$FFLAGS"
+        ( set +e ; fpm run  --example false-assertion   ${FPM_FLAGS} --flag "$FFLAGS -DASSERTIONS" ; test $? = $ERROR_STOP_CODE )
+        ( set +e ; fpm run  --example invoke-via-macro  ${FPM_FLAGS} --flag "$FFLAGS -DASSERTIONS" ; test $? = $ERROR_STOP_CODE )