Group cpp_dummy_build test into an existing component

No need to do yet another build just to compile an additional trivial program.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 12affa1..9295c9d 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -1542,12 +1542,15 @@
 component_test_full_cmake_clang () {
     msg "build: cmake, full config, clang" # ~ 50s
     scripts/config.py full
-    CC=clang cmake -D CMAKE_BUILD_TYPE:String=Release -D ENABLE_TESTING=On .
+    CC=clang CXX=clang cmake -D CMAKE_BUILD_TYPE:String=Release -D ENABLE_TESTING=On -D TEST_CPP=1 .
     make
 
     msg "test: main suites (full config, clang)" # ~ 5s
     make test
 
+    msg "test: cpp_dummy_build (full config, clang)" # ~ 1s
+    programs/test/cpp_dummy_build
+
     msg "test: psa_constant_names (full config, clang)" # ~ 1s
     tests/scripts/test_psa_constant_names.py
 
@@ -1842,15 +1845,6 @@
     tests/scripts/depends.py pkalgs
 }
 
-component_test_make_cxx () {
-    msg "build: Unix make, full, gcc + g++"
-    scripts/config.py full
-    make TEST_CPP=1 lib programs
-
-    msg "test: cpp_dummy_build"
-    programs/test/cpp_dummy_build
-}
-
 component_build_module_alt () {
     msg "build: MBEDTLS_XXX_ALT" # ~30s
     scripts/config.py full