make/info-build: Protect shell from parentheses in CFLAGS

As for why the `-e` is being removed, observe that the `-e` would
otherwise be printed; there is an [elaborate treatise] on what happens
there.

[elaborate treatise]: https://unix.stackexchange.com/questions/700675/why-is-echo-e-behaving-weird-in-a-makefile

makefiles/info.inc.mk

@@ -82,7 +82,7 @@ info-build:
 	@echo -e 'INCLUDES:$(patsubst %, \n\t%, $(INCLUDES))'
 	@echo ''
 	@echo 'CC:      $(CC)'
-	@echo -e 'CFLAGS:$(patsubst %, \n\t%, $(CFLAGS))'
+	@echo 'CFLAGS:$(patsubst %, \n\t%, $(subst ','"'"',$(CFLAGS)))'
 	@echo ''
 	@echo 'CXX:     $(CXX)'
 	@echo -e 'CXXUWFLAGS:$(patsubst %, \n\t%, $(CXXUWFLAGS))'