Hack for "true" and "false" used as enum element values

This is not a full solution by far, but should address the most common case.

This also allows "cpp_enum" unit test to pass.

Examples/test-suite/c/Makefile.in

@@ -51,7 +51,6 @@ FAILING_CPP_TESTS := \
     cpp_basic_global_var_class \
     cpp_basic_template_class \
     cpp_basic_template_function \
-    cpp_enum \
     c_backend_cpp_natural_std_string \
     c_backend_cpp_exception \
     default_args \

Examples/test-suite/c/cpp_enum_runme.c

@@ -63,10 +63,10 @@ int main(int argc, const char *argv[]) {
 	play_state t;
 
 	t = PLAY;
-	assert(t == true);
+	assert(t == 1);
 
 	t = STOP;
-	assert(t == false);
+	assert(t == 0);
 
 	return 0;
-}
+}

Source/Modules/c.cxx

@@ -1774,6 +1774,17 @@ ready:
 	Append(cvalue, "'");
       }
 
+      // Boolean constants can't appear in C code neither, so replace them with their values in the simplest possible case. This is not exhaustive, of course,
+      // but better than nothing and doing the right thing is not simple at all as we'd need to really parse the expression, just textual substitution wouldn't
+      // be enough (consider e.g. an enum element called "very_true" and another one using it as its value).
+      if (Cmp(value, "true") == 0) {
+	Clear(cvalue);
+	Append(cvalue, "1");
+      } else if (Cmp(value, "false") == 0) {
+	Clear(cvalue);
+	Append(cvalue, "0");
+      }
+
       Printv(f_wrappers_types, " = ", cvalue, NIL);
 
       Delete(cvalue);