v.io/jiri: add policy driven flags for merging environment variables.

- Also tidy up v23-profile env, list etc.

MultiPart: 5/11

Change-Id: I4dcadb3890e585182c11a208e8157d8f2df58a28
diff --git a/Makefile b/Makefile
index 9943a3d..6cb32b8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 SHELL := /bin/bash -euo pipefail
 
-NODE_DIR := $(shell jiri v23-profile env --profile=nodejs V23_TARGET_INSTALLATION_DIR=)
+NODE_DIR := $(shell jiri v23-profile list --info Target.InstallationDir nodejs)
 export PATH := $(JIRI_ROOT)/release/go/bin:node_modules/.bin:$(NODE_DIR)/bin:clients/shell/go/bin:$(PATH)
 export GOPATH := $(shell pwd)/clients/shell/go:$(GOPATH)
 export VDLPATH := $(shell pwd)/clients/shell/go/src:$(JIRI_ROOT)/release/go/src