build: only try to find node when it's needed by the target

Right now `node -p process.versions.openssl` always gets run
in the Makefile even when it's not needed by the target
(e.g. `make clean`, `make test-only`). This patch makes it
a run time call instead of part of the global expansion.

PR-URL: nodejs#24115
Reviewed-By: Richard Lau <[email protected]>
Reviewed-By: Daniel Bevenius <[email protected]>

Makefile

@@ -332,16 +332,16 @@ ifeq ($(OSTYPE),aix)
 DOCBUILDSTAMP_PREREQS := $(DOCBUILDSTAMP_PREREQS) out/$(BUILDTYPE)/node.exp
 endif
 
-node_use_openssl = $(shell $(call available-node,"-p" \
-		   "process.versions.openssl != undefined"))
+node_use_openssl = $(call available-node,"-p" \
+		   "process.versions.openssl != undefined")
 test/addons/.docbuildstamp: $(DOCBUILDSTAMP_PREREQS) tools/doc/node_modules
-ifeq ($(node_use_openssl),true)
-	$(RM) -r test/addons/??_*/
-	[ -x $(NODE) ] && $(NODE) $< || node $<
-	touch $@
-else
-	@echo "Skipping .docbuildstamp (no crypto)"
-endif
+	@if [ "$(shell $(node_use_openssl))" != "true" ]; then \
+		echo "Skipping .docbuildstamp (no crypto)"; \
+	else \
+		$(RM) -r test/addons/??_*/; \
+		[ -x $(NODE) ] && $(NODE) $< || node $< ; \
+		touch $@; \
+  fi
 
 ADDONS_BINDING_GYPS := \
 	$(filter-out test/addons/??_*/binding.gyp, \
@@ -609,11 +609,11 @@ apidocs_json = $(addprefix out/,$(apidoc_sources:.md=.json))
 apiassets = $(subst api_assets,api/assets,$(addprefix out/,$(wildcard doc/api_assets/*)))
 
 tools/doc/node_modules: tools/doc/package.json
-ifeq ($(node_use_openssl),true)
-	cd tools/doc && $(call available-node,$(run-npm-ci))
-else
-	@echo "Skipping tools/doc/node_modules (no crypto)"
-endif
+	@if [ "$(shell $(node_use_openssl))" != "true" ]; then \
+		echo "Skipping tools/doc/node_modules (no crypto)"; \
+	else \
+		cd tools/doc && $(call available-node,$(run-npm-ci)) \
+  fi
 
 .PHONY: doc-only
 doc-only: tools/doc/node_modules \