Fix a typo in the makefile to actually not recompile files more than necessary.

Makefile.distrib

@@ -411,14 +411,14 @@ misc/q_symbol.cmo: misc/q_symbol.ml
 parser/parser.$(EXTENSION): PACKAGES += camlp4.extend
 
 
-DUMMY := $(shell test ! -f build_flags -o \
-      \( "$(FORPACKOPT) $(SYNTAX_PARSER) $(INCLUDES) $(EXTRA_LINK_OPTS)" != \
-      	 "$(cat build_flags)" \) && \
+DUMMY := $(shell (test ! -f build_flags -o \
+      \( '$(FORPACKOPT) $(SYNTAX_PARSER) $(INCLUDES) $(EXTRA_LINK_OPTS)' != \
+      	 "$$(cat build_flags)" \) && \
 	 	rm -f build_flags && \
-		   echo $(FORPACKOPT) $(SYNTAX_PARSER) $(INCLUDES) $(EXTRA_LINK_OPTS) > build_flags )
+		   printf "%s" '$(FORPACKOPT) $(SYNTAX_PARSER) $(INCLUDES) $(EXTRA_LINK_OPTS)' > build_flags) || true )
 
 build_flags:
-	$(HIDE) echo $(FORPACKOPT) $(SYNTAX_PARSER) $(INCLUDES) $(EXTRA_LINK_OPTS) > build_flags
+	$(HIDE) printf "%s" '$(FORPACKOPT) $(SYNTAX_PARSER) $(INCLUDES) $(EXTRA_LINK_OPTS)' > build_flags
 
 %.cmo: %.ml build_flags
 	@echo "Build $@"
@@ -428,7 +428,7 @@ build_flags:
 	@echo "Build $@"
 	$(HIDE) $(CAMLOPT) $(FORPACKOPT) -c $(SYNTAX_PARSER) $(INCLUDES) $<
 
-%.cmi: %.mli build_flags
+%.cmi: %.mli
 	@echo "Build $@"
 	$(HIDE) $(CAMLC) -c $(SYNTAX_PARSER) $(INCLUDES) $<