tools: make test-npm work without global npm

Futher discussion at nodejs/node-v0.x-archive#25294

PR-URL: #1926
Reviewed-By: Rod Vagg <[email protected]>
Reviewed-By: Michael Dawson <[email protected]>

Author: Fishrock123

tools/test-npm.sh

@@ -30,7 +30,8 @@ export npm_config_tmp="npm-tmp"
 
 # install npm devDependencies and run npm's tests
 ../$NODE_EXE cli.js install --ignore-scripts
-../$NODE_EXE cli.js run-script test-all
+../$NODE_EXE cli.js run-script test-legacy
+../$NODE_EXE cli.js run-script test
 
 # clean up everything one single shot
 cd .. && rm -rf test-npm