iwyu.yml: also run test/cfg with libc++

Author: firewave

.github/workflows/iwyu.yml

@@ -202,7 +202,6 @@ jobs:
 
       # TODO: run with all configurations
       - name: test/cfg
-        if: matrix.stdlib == 'libstdc++'
         run: |
           # TODO: redirect to log
           ./test/cfg/runtests.sh

test/cfg/runtests.sh

@@ -265,7 +265,6 @@ function sqlite3_fn {
 
 # openmp.c
 function openmp_fn {
-    # TODO: omp.h not found with IWYU
     # MacOS compiler has no OpenMP by default
     if ! command -v sw_vers; then
       echo "OpenMP assumed to be present, checking syntax with ${CC} now."